CA2160352C - Ultra-wideband radar motion sensor - Google Patents
Ultra-wideband radar motion sensor Download PDFInfo
- Publication number
- CA2160352C CA2160352C CA002160352A CA2160352A CA2160352C CA 2160352 C CA2160352 C CA 2160352C CA 002160352 A CA002160352 A CA 002160352A CA 2160352 A CA2160352 A CA 2160352A CA 2160352 C CA2160352 C CA 2160352C
- Authority
- CA
- Canada
- Prior art keywords
- pulses
- uwb
- baseband
- output signal
- radar pulses
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/28—Details of pulse systems
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
- G01S13/887—Radar or analogous systems specially adapted for specific applications for detection of concealed objects, e.g. contraband or weapons
- G01S13/888—Radar or analogous systems specially adapted for specific applications for detection of concealed objects, e.g. contraband or weapons through wall detection
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/05—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves
- A61B5/0507—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves using microwaves or terahertz waves
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
- G01S13/0209—Systems with very large relative bandwidth, i.e. larger than 10 %, e.g. baseband, pulse, carrier-free, ultrawideband
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
- G01S13/06—Systems determining position data of a target
- G01S13/08—Systems for measuring distance only
- G01S13/10—Systems for measuring distance only using transmission of interrupted, pulse modulated waves
- G01S13/18—Systems for measuring distance only using transmission of interrupted, pulse modulated waves wherein range gates are used
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
- G01S13/50—Systems of measurement based on relative movement of target
- G01S13/52—Discriminating between fixed and moving objects or between objects moving at different speeds
- G01S13/56—Discriminating between fixed and moving objects or between objects moving at different speeds for presence detection
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/69—Spread spectrum techniques
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/69—Spread spectrum techniques
- H04B1/7163—Spread spectrum techniques using impulse radio
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/72—Signal processing specially adapted for physiological signals or for diagnostic purposes
- A61B5/7235—Details of waveform analysis
- A61B5/7239—Details of waveform analysis using differentiation including higher order derivatives
Abstract
A motion sensor is based on ultra-wideband (UWB) radar.
UWB radar range is determined by a pulse-echo interval. For motion detection, the sensors operate by staring at a fixed ranged and then sensing any change in the averaged radar reflectivity at that range. A sampling gate is opened at a fixed delay after the emission of a transmit pulse. The resultant sampling gate output is averaged over repeated pulses. Changes in the averaged sampling gate output represent changes in the radar reflectivity at a particular range, and thus motion.
UWB radar range is determined by a pulse-echo interval. For motion detection, the sensors operate by staring at a fixed ranged and then sensing any change in the averaged radar reflectivity at that range. A sampling gate is opened at a fixed delay after the emission of a transmit pulse. The resultant sampling gate output is averaged over repeated pulses. Changes in the averaged sampling gate output represent changes in the radar reflectivity at a particular range, and thus motion.
Description
-i-ULTRA-WIDEBAND RADAR MOTION SENSOR
BACKGROUND OF THE INVENTION
The invention relates generally to motion sensors and more particularly to motion sensors based on ultra-wideband radar.
Motion sensors are primarily based on ultrasound, passive infrared (PIR) and radar detectors. Ultrasonic motion sensors are commonly used for automatic door openers and security alarms. They are of low cost and can operate with narrow beamwidths. However, installation options are limited since ultrasonic beams are easily blocked by thin materials, including paper. Another short-coming is the tendency to false trigger on reflections from blowing curtains or flying insects.
PIR sensors. are perhaps the most frequently used home security sensor. They use a special Fresnel lens to generate multiple thermal images of a .warm object, such as a person. As the person traverses the field of view, the thermal images produce periodic fluctuations as they sweep across an IR sensor element, which are then detected by low cost electronics. As with ultrasound, PIR can be blocked by a sheet of paper. Furthermore, PIR has no range adjustment.
FM-CW radar sensors emit a swept frequency microwave signal and compare the frequency of the echo with its current emission frequency, producing a beat frequency proportional to range. FM-GW
radar sensors use low cost microwave oscillators and detector diodes, and audio frequency processing electronics to determine the audio beat frequency, or range. Non-ranging radar sensors simply emit a .
continuous microwave carrier and listen for a Doppler shift from a moving object. The antennas are usually low cost, die cast metal horns.
i PCTIUS94~U3892 The main limitations to FM-CW and Doppler radar are: 1) limited materials penetration due to the high microwave frequencies employed, 2) microphonics caused by the use of short radar wavelengths combined with audio frequency processing, 3) frequency crowding, and 4) poor short-range operation Short range performance is limited by close-in noise sidebands in the transmit oscillator, which must operate in the gigaHertz region and yet not have random frequency variations on the order of 100Hz, since this variation would be indistinguishable from the desired beat frequencies.
Si TMMARY OF THE INVENTION
Ultra wideband (UVYB) radar motion sensing is a completely new approach to motion sensor technology. UWB radar operates as a pulse-echo system that clocks the two-way time of flight of a very short electrical pulse. A carrier frequency is not used; instead, an electrical voltage pulse is applied directly to the antenna.
Since frequency up-conversion by a modulator is not used, there is no frequency to tune in. The UWB transmit spectrum is the _ Fourier transform of the emitted pulse and generally spans hundreds of megaHertz to several gigaHertz. It is inherently spread~pectrum. A
frequency allocation by the FCC is not relevant. . Furthermore, many independent UWB sensors may be co-located without interference.
By not using frequency up-conversion, the UWB spectrum is located as dose to DC as possible. Since most materials exhibit rapidly increasing attenuation with frequency, UWB radar has a very significant advantage in materials penetration. Tests show that 200ps pulses freely penetrate gypsum, wood, and rnncrete walls. Excellent materials penetration is a fundamental advantage to UWB sensors, and will allow their-installation behind walls and appliance panels, above ceilings and below floors.
UWB radar range is determined by the pulse-echo interval.
For motion detection, the sensors operate by staring at a fixed range and then sensing any change in the averaged radar reflectivity at that range.
This is accomplished by opening a sampling gate at a fixed delay after the emission of the transmit pulse, and then averaging the resultant sampling gate output over repeated pulses. Changes in the averaged sampling gate output represent changes in the radar reflectivity at a particular range, and thus motion.
BACKGROUND OF THE INVENTION
The invention relates generally to motion sensors and more particularly to motion sensors based on ultra-wideband radar.
Motion sensors are primarily based on ultrasound, passive infrared (PIR) and radar detectors. Ultrasonic motion sensors are commonly used for automatic door openers and security alarms. They are of low cost and can operate with narrow beamwidths. However, installation options are limited since ultrasonic beams are easily blocked by thin materials, including paper. Another short-coming is the tendency to false trigger on reflections from blowing curtains or flying insects.
PIR sensors. are perhaps the most frequently used home security sensor. They use a special Fresnel lens to generate multiple thermal images of a .warm object, such as a person. As the person traverses the field of view, the thermal images produce periodic fluctuations as they sweep across an IR sensor element, which are then detected by low cost electronics. As with ultrasound, PIR can be blocked by a sheet of paper. Furthermore, PIR has no range adjustment.
FM-CW radar sensors emit a swept frequency microwave signal and compare the frequency of the echo with its current emission frequency, producing a beat frequency proportional to range. FM-GW
radar sensors use low cost microwave oscillators and detector diodes, and audio frequency processing electronics to determine the audio beat frequency, or range. Non-ranging radar sensors simply emit a .
continuous microwave carrier and listen for a Doppler shift from a moving object. The antennas are usually low cost, die cast metal horns.
i PCTIUS94~U3892 The main limitations to FM-CW and Doppler radar are: 1) limited materials penetration due to the high microwave frequencies employed, 2) microphonics caused by the use of short radar wavelengths combined with audio frequency processing, 3) frequency crowding, and 4) poor short-range operation Short range performance is limited by close-in noise sidebands in the transmit oscillator, which must operate in the gigaHertz region and yet not have random frequency variations on the order of 100Hz, since this variation would be indistinguishable from the desired beat frequencies.
Si TMMARY OF THE INVENTION
Ultra wideband (UVYB) radar motion sensing is a completely new approach to motion sensor technology. UWB radar operates as a pulse-echo system that clocks the two-way time of flight of a very short electrical pulse. A carrier frequency is not used; instead, an electrical voltage pulse is applied directly to the antenna.
Since frequency up-conversion by a modulator is not used, there is no frequency to tune in. The UWB transmit spectrum is the _ Fourier transform of the emitted pulse and generally spans hundreds of megaHertz to several gigaHertz. It is inherently spread~pectrum. A
frequency allocation by the FCC is not relevant. . Furthermore, many independent UWB sensors may be co-located without interference.
By not using frequency up-conversion, the UWB spectrum is located as dose to DC as possible. Since most materials exhibit rapidly increasing attenuation with frequency, UWB radar has a very significant advantage in materials penetration. Tests show that 200ps pulses freely penetrate gypsum, wood, and rnncrete walls. Excellent materials penetration is a fundamental advantage to UWB sensors, and will allow their-installation behind walls and appliance panels, above ceilings and below floors.
UWB radar range is determined by the pulse-echo interval.
For motion detection, the sensors operate by staring at a fixed range and then sensing any change in the averaged radar reflectivity at that range.
This is accomplished by opening a sampling gate at a fixed delay after the emission of the transmit pulse, and then averaging the resultant sampling gate output over repeated pulses. Changes in the averaged sampling gate output represent changes in the radar reflectivity at a particular range, and thus motion.
An invisible, constant-range spherical shell is effectively projected into space, the thickness of which is directly related to the radar pulse width In two illustrative embodiments, one sensor has a shell thickness of one inch, and the other about 18 inches.
The location of the detection shell is set by adjusting the sampling gate delay. This delay adjustment is easily implemented, and can be adjusted down to point blank range with no performance penalty.
User adjustable detection range is another outstanding feature of UWB
sensors.
The cost of UWB motion sensors will be on a par with_ competing sensors, so its selection as the most appropriate sensor technology for many applications will be assured. Near term UWB
sensors will be built with off-the-shelf components. Eventually, a silicon, application specific integrated circuit {AS1C) may embody all the sensor electronics.
UVhB motion sensor electronics may also be connected -to electro-optical transducers, such as light emitting- diodes and PIN
photodiodes to project the detection shell optically. This would be particularly useful where pencil beam sensing, i.e., "light saber"
operation is desired.
According to an aspect of the present invention there is provided a method of using ultra-wideband (UWB) radar pulses, comprising the steps of transmitting the UWB
radar pulses, receiving and processing reflected UWB radar pulses by detecting the reflected UWB radar pulses from a predetermined range and by producing a baseband detection output signal indicative of a plurality of the detected pulses, integrating the baseband detection output signal, thereby producing a baseband average output signal corresponding to an average of the plurality of the detected pulses, and differentiating baseband average output signals produced at different times, thereby detecting motion.
According to another aspect of the present invention there is provided a method of using ultra-wideband (UWB) radar pulses, comprising the steps of transmitting the UWB radar pulses, receiving and processing reflected UWB radar pulses by detecting the reflected UWB radar pulses from a predetermined range and by producing a baseband of detection output signal indicative of a plurality of the detected pulses, differentiating baseband detection output signals produced at different times, thereby producing a baseband differentiation output signal, and integrating the baseband differentiation output -3 a-signal, thereby detecting motion.
According to a further aspect of the present invention there is provided a method of using ulixa-wideband (UWB) radar pulses, comprising the steps of transmitting the UWB radar pulses, and receiving and processing reflected UWB radar pulses by detecting the reflected UWB radar pulses by detecting the reflected UWB radar pulses from a predetermined range and by producing a baseband detection output signal indicative of a plurality of the pulses, characterized in that the step of producing a detection output signal comprises a step of integrating the reflected UWB
radar pulses, the detection output signal corresponding to an average of the plurality of the reflected pulses, and in that the method further comprises the steps of integrating the baseband detection output signal, thereby producing a baseband average output signal corresponding to a further average of the plurality of the reflected pulses, and differentiating baseband average output signals produced at different times, thereby detecting motion.
According to a further aspect of the present invention there is provided a method of using ultra-wideband (UWB) radar pulses, comprising the steps of transmitting the UWB radar pulses, and receiving and processing reflected UWB radar pulses by detecting the reflected UWB radar pulses from a predetermined range and by producing a baseband detection output signal indicative of the pulses, characterized in that the step of producing a detection output signal comprises a step of integrating the reflected UWB
radar pulses, the detection output signal corresponding to an average of the plurality of the reflected pulses, and in that the method further comprises the steps of differentiating baseband detection output signals produced at different times, thereby producing a baseband differentiation output signal, and integrating the baseband differentiation output signal, thereby detecting motion.
BRIEF DESCRIIyI ION OF TFiE DRAWINGS
Figure I is a block diagram of a UWB radar motion sensor.
Figure 2 illustrates a UWB radar constant range shell.
Figures 3a-d are various UWB radar motion detection signals.
Figure 4 is a schematic diagram of a tJWB receiver in a UWB radar motion detector.
Figure 5 is a schematic diagram of a tJWB rad=.r motion sensor.
-3b-Figure 6 is a schematic diagram of a VHF medium range UWB radar motion sensor.
Figure 7 shows dipole antenna pair ringdown.
Figures 8a-b show UWB spectrum with non-dithered and dithered PRI operation Figure 9 illustrates dual shell velocity measurement.
Figure ~ 10 is a schematic diagram of a time multiplexed dual range shell velocity measurement system.
The location of the detection shell is set by adjusting the sampling gate delay. This delay adjustment is easily implemented, and can be adjusted down to point blank range with no performance penalty.
User adjustable detection range is another outstanding feature of UWB
sensors.
The cost of UWB motion sensors will be on a par with_ competing sensors, so its selection as the most appropriate sensor technology for many applications will be assured. Near term UWB
sensors will be built with off-the-shelf components. Eventually, a silicon, application specific integrated circuit {AS1C) may embody all the sensor electronics.
UVhB motion sensor electronics may also be connected -to electro-optical transducers, such as light emitting- diodes and PIN
photodiodes to project the detection shell optically. This would be particularly useful where pencil beam sensing, i.e., "light saber"
operation is desired.
According to an aspect of the present invention there is provided a method of using ultra-wideband (UWB) radar pulses, comprising the steps of transmitting the UWB
radar pulses, receiving and processing reflected UWB radar pulses by detecting the reflected UWB radar pulses from a predetermined range and by producing a baseband detection output signal indicative of a plurality of the detected pulses, integrating the baseband detection output signal, thereby producing a baseband average output signal corresponding to an average of the plurality of the detected pulses, and differentiating baseband average output signals produced at different times, thereby detecting motion.
According to another aspect of the present invention there is provided a method of using ultra-wideband (UWB) radar pulses, comprising the steps of transmitting the UWB radar pulses, receiving and processing reflected UWB radar pulses by detecting the reflected UWB radar pulses from a predetermined range and by producing a baseband of detection output signal indicative of a plurality of the detected pulses, differentiating baseband detection output signals produced at different times, thereby producing a baseband differentiation output signal, and integrating the baseband differentiation output -3 a-signal, thereby detecting motion.
According to a further aspect of the present invention there is provided a method of using ulixa-wideband (UWB) radar pulses, comprising the steps of transmitting the UWB radar pulses, and receiving and processing reflected UWB radar pulses by detecting the reflected UWB radar pulses by detecting the reflected UWB radar pulses from a predetermined range and by producing a baseband detection output signal indicative of a plurality of the pulses, characterized in that the step of producing a detection output signal comprises a step of integrating the reflected UWB
radar pulses, the detection output signal corresponding to an average of the plurality of the reflected pulses, and in that the method further comprises the steps of integrating the baseband detection output signal, thereby producing a baseband average output signal corresponding to a further average of the plurality of the reflected pulses, and differentiating baseband average output signals produced at different times, thereby detecting motion.
According to a further aspect of the present invention there is provided a method of using ultra-wideband (UWB) radar pulses, comprising the steps of transmitting the UWB radar pulses, and receiving and processing reflected UWB radar pulses by detecting the reflected UWB radar pulses from a predetermined range and by producing a baseband detection output signal indicative of the pulses, characterized in that the step of producing a detection output signal comprises a step of integrating the reflected UWB
radar pulses, the detection output signal corresponding to an average of the plurality of the reflected pulses, and in that the method further comprises the steps of differentiating baseband detection output signals produced at different times, thereby producing a baseband differentiation output signal, and integrating the baseband differentiation output signal, thereby detecting motion.
BRIEF DESCRIIyI ION OF TFiE DRAWINGS
Figure I is a block diagram of a UWB radar motion sensor.
Figure 2 illustrates a UWB radar constant range shell.
Figures 3a-d are various UWB radar motion detection signals.
Figure 4 is a schematic diagram of a tJWB receiver in a UWB radar motion detector.
Figure 5 is a schematic diagram of a tJWB rad=.r motion sensor.
-3b-Figure 6 is a schematic diagram of a VHF medium range UWB radar motion sensor.
Figure 7 shows dipole antenna pair ringdown.
Figures 8a-b show UWB spectrum with non-dithered and dithered PRI operation Figure 9 illustrates dual shell velocity measurement.
Figure ~ 10 is a schematic diagram of a time multiplexed dual range shell velocity measurement system.
Figure 11 is a schematic diagram of a dual delay velocity measurement system.
Figure 12A is a schematic diagram of a modulated Colpitts RF oscillator circuit.
Figure 12B is an output signal from the circuit of Figure 12A.
pETAILED DESCRIPTTON OF THE PREFERRED F1~ODIMENTS
Referring to Figure 1, a free-running oscillator (PRI
generator) 20 generates the radar pulse repetition interval (PR'n.
Typically, this interval is lus. A noise generator 22 is connected to the PRI generator 20 to introduce a random variation to the PRI, for purposes to be described below. The output of the PRI generator 20 drives two delay means, a fixed reference delay means 24 in the transmit path 26, and an adjustable delay means 28 in the receive (gating pulse) path 30. Delay means 28 is adjusted by range adjustment means 32.
The reference delay means 24 is generally set to match the minimum delay in the receive path 30, and may also be set to account . for delays in the antenna feed lines, etc. The output of the reference delay means 24 drives an impulse (or step) generator 34 which provides the transmit pulse. If PRI generator 20 or reference delay means 24 produce a pulse with sufficiently fast rise time, then impulse (or step) generator 34 may be omitted. Otherwise, generator 34 is used to generate a suitable transmit pulse. The transmit pulse typically resembles a Gaussian shaped voltage pulse. In general, it is not a modulated RF
pulse. The UWB radar differs from conventional radar in that no carrier frequency is used. Rather, a sequence of individual poises, spaced by the PRI, is applied directly to the antenna.
The transmit pulse is directly radiated by the transmit antenna 36. There are several UWB antennas in common use, the most common of which is the tapered slot antenna, also known as an endfire antenna. In preferred embodiments, both simple wire dipoles and broader band 'bow-tie" dipoles are used. Due to their resonant nature, ringing is produced in the emitted radiation, but this effect is put to use, as will be described below.
Since many antennas exhibit increasing gain with increasing frequency, a step input applied to the transmit.antenna will result in the radiation of the derivative of the step, i.e., an impulse. In the embodiments of Figures 5 and 6, a voltage step is applied to the transmit antenna. Both the transmit and -receive antenna feedline may contain spectrum limiting or shaping filters for various purposes known to those skilled in the art.
The receive antenna 38 is connected to a UWB detector {receiver or sampler) 40, which is described in United States Patent No.
, 3 4 5 , 4 71 ~. The UWB detector may also be a wideband sampling circuit, such as those incorporated by Tektronix, Inc. and Hewlett-Packard, Inc. in their standard sampling oscilloscopes. The samp3er 40 is gated or strobed by. the output of the adjustable delay 28 through impulse (or step) generator 42, thus causing the sampler 40 to sample a point in space corresponding to the two-way echo time to the target 44. Again, impulse/step generator 42 may be omitted if the adjustable delay pulse has sufficiently short risetime. ~ ' The output of the IJVVB detector 40 is averaged in an integrator 46 with a time constant that is substantially longer than the PRI of the radar, typically lOms in a motion sensor. At a PRI of Tits,. .
10,000 pulses are averaged. This average value represents the sum of the radar reflections and other radar clutter, such as direct antenna to antenna coupling., The method can be-implernented by averaging two or more pulses: However, preferably a- large number, i.e. 1,000 to 10,000 pulses, vrrill be averaged. The transmitted pulses typically have a pulse width of about 5ns or less, and more preferably about lns or less. The PIZI
typically is in the range of 100ns to 100ms.
If the radar reflectivity changes at the range being sampled, the average will change, and this change is sensed by the differentiator 48. The output of the differentiator 48 triggers a rnmparator circuit 50, which in turn can activate an alarm. Comparator 50 compares the . output of differentiator 48 to a preset Vref. The sensitivity is controlled by Vref.
For simplicity, this invention uses an analog integrator and differentiator. A digital equivalent may be used at added complexity. In linear systems, the order of the integrator and differentiator may be interchanged. Further, the cascaded integration and differentiation wo 9anas~9 216 0 3 5 2 rcr~s9aio~s92 process resembles a bandpass filter in the frequency domain, and so a bandpass filter 52 maybe used for this combined function. Typical filter constants are: low frequency corner at 1Hz and high frequency come: at lOHz, for motion sensing of people.
The UWB pulse~cho system 54 typically operates at a constant sampling delay, or at a constant range, as depicted in Figure 2.
Due to the short impulse emitted, an effective spherical shell 56 is projected in space. The thickness of the shell is directly related to the sampling pulse width, which is generally set to be equal to the transmit pulse width T. The constant range shell then has a thickness of cT/2 where c is the pulse velocity.
Figures 3a-d show data obtained from the UWB radar of Figure 5. The horizontal scales are a slow time axis, corresponding to a 2 second time lapse. The vertical scale is the output from the UWB
detector-integrator-differentiator. In Figures 3a-d, a human hand is inserted into and then removed from the shell W thin the two second time scale, and the resulting signals are indicated for several ranges (1 ft.
in Figure 3a, 4 ft. in Figure 3b,15 in. in Figures 3c-d), and with several materials (6 in. of text books in Figure 3c, 2 in. of concrete in Figure 3d) between the radar and the target. Both insertion and removal of the hand are clearly shown.
Figure 4 shows a differential UWB receiver designed for use in UWB radar motion detector. A broadband dipole antenna 58 is .
connected to a tvrristed pair transmission line 60. Each wire of line pair 60 is rnnnected through a capacitor C1 or C2 and series resistor Rl or R2 to the positive input of an operational amplifier A1 or A2. The junctions between Cl-Rl and C2 R2 are connected to a pair of diodes Dl, D2 whose anodes are connected to the junctions and whose cathodes are connected together. A gating pulse is applied to the common cathode junction between Dl-D2. The gating pulse line may indude a capacitor Cs. The input line pair 60 and gating pulse input line are all terminated in resistors RT. The positive inputs of Al, A2 are also connected through resistors R3, R4 respectively to a + Bias voltage. The positive inputs of Al, A2 are also connected through capacitors C3, C4 to ground.
C3 and C4 can be omitted if there is sufficient input capacitance on A1, A2, or if RF rejection is not necessary or desired: The output of A1 is connected through C5 and R5 to the negative input of operational _7_ amplifier A3 and the output of AZ is connected to the positive input of A3. The output of A3 is fed back to the negative input of A3 through .
capacitor C6 and parallel variable resistor R6. Resistor R6 is adjusted to control sensitivity. The negative inputs of A1, A2 are connected together through C7 and R7 and are connected to the output of Al, A2 through C8 and parallel R8.
In an illustrative embodiment Cl=C2=22pF, RI=R2=lOK, RT=68 ohm, DI and D2 are M-Pulse MP2612 diodes, the gate pulse is -8V
with 200ps edge and 1Ns PRI generated by Metellics step recovery diode MMD 805-828 input through a 0.5 pF capacitor, R3=R4=IOM, +Bias=+5V, C3~4~.01itF, A1 A3 are TLfl74 op amps, C5 =2201.tF, R5=1K, C6~.2NF, R6=I00K (variable), C7=4.71tF, R7=47K, C8~300pF, R8 = 2.2M. If C3, C4 are omitted, then Cl=C2=O.O1N.F.
Figure S is a schematic of a micropower UWB radar motion sensor. A series of CMOS logic gates (labeled Il) form the PRI generator (33kHz oscillator) 21, which is connected through buffer gates (IZ) to the delay circuits 23ab and the impulse generators 25ab. Noise generator 19 is connected to oscillator 21. The delay means 23a is just the wire (i.e. no delay), while the delay means 23b is formed of the resistors associated with. switch S. The impulses are finally generated by step recovery diodes (SRD), supplied by Metellics Corp. of Sunnyvale, CA and specified to produce Imps transitions or faster. The transmit (T'~ and receiver (R) antennas are 6" bow-tie shaped dipoles or 3" wire monopoles. The UWB receiver 27 formed of op amps (I3) is of the type shown in Figure 4 and contains the integrator and differentiator in the form of various capacitors associated with the circuit. The switch S in the gating pulse path and in the UWB receiver is used to select the range (6' or 12'). An alarm circuit 29 is comprised of op amps I4, and includes a bipolar comparator and a driver circuit to sound an alarm after detection. The IC's are Il=CD4069, I2 74HC04, I3=TLC27L4, I4=TLC27L2. Not shown are a +3V voltage regulator and +6V penlight batteries. Because of the low duty cycle and small power consumption, the batteries last for several years in continuous operation.
Figure 6 shows a VIA security alarm circuit, operating at a transmit pulse width of 2ns. The waveform that is applied to the .18"
dipole antenna 31 is essentially a voltage step that is effectively differentiated, with ringing, by the antenna. The PRI generator {100 kHz 2160352 ~ ' PCTlUS94~03892 _g_ oscillator) 21, and buffers in the transmit and receive (strobe) paths are formed by CMOS IC's h and I2, which are 74HC04 inventors. This IC
costs less than $0.50 and generates stable, fitter-free delays trorn ~.ero to 200ns. Delay means 23a provides no delay, while delay means 23b is formed of pofientiometer R The impulse generators 25a~ include transistors Ql=2N5I09 and Q2=2N2369. Noise generator 19 is connected to oscillator 21. The two halves Slab of a dipole antenna are connected to the inputs of UWB receiver 27 which drives alarm circuit 29. The IC's are I3 TLC27L4 and I4=TLC271r2 op amps. The Schottky diodes D are 1N5711. Range delay adjustment is provided by a simple potentiometer R in the strobe line. This circuit is similar to Figure 5. It runs on batteries and its antennas are one meter in length rather than 6".
The invention is thus based on RCS (radar cross section) averaging at a fixed range cell using averaging circuits, plus averaged RCS change detection A fixed range is stared at, and a large number of return pulses are averaged. Changes in the average are then sensed as motion.
The invention also includes RCS averaging across a range sweep using averaging, plus averaged RCS change detection. Virtually _ all pulse-echo radars sweep the adjustable delay, or range delay, across a span while averaging a relatively small number of pulses, so individual "blips" may show up. In this invention, the averaging time constant can be set to be larger than the range scan Lane such that the entire sweep is averaged. Changes in this average represent motion somewhere within the range sweep.
Although individual "blips", or targets at particular ranges are diminished by the averaging process, noise levels are equally reduced by the averaging process, so the signal-to-noise ratio for changes in the blip remains the same. UWB reflections off people are a highly variable function of aspect angle, so a person moving within the averaged range sweep will produce a detectable fluctuation. This sweep averaging technique is intended as a simplification to UWB motion sensor hardware.
The invention also includes an antenna ringdown method of motion detection across a range span, using averaging circuits, plus averaged RCS change detection. Figure 7 shows typical antenna-ringdown produced'by a transmit/receive dipole pair when excited by a _216032 WO 9411,4579 PCT/US94103892 fast rising voltage step. UWB motion sensors operate primarily at a detection range corresponding to the time of flight of the leading edge of the transmitted pulse. Ringing that is trailing the leading edge appears later in time, while in space, ringing appears at a range closer to the radar, for a fixed sampling delay. Thus, for a given range delay setting, ringing pulses generate an outermost detection shell corresponding to the leading pulse, and successive inner detection shells located by the periodicity of the ringing.
The advantage to ringing is that it generates an effective range sweep since multiple ranges become active for motion sensing.
Yet, range sweeping hardware is eliminated and the use of simple dipole antennas is allowed.
Another advantage to this technique, or to an averaged range sweep, is that if a target manages to evade the outer detection shell, the inner shells may still be activated. This situation occurs when the target echo from the outer range shell is too small to be detected. It also prevents a person from walking up to a UWB motion detector without setting it off.
As the antenna rings down, ringing amplitude decreases.
-Since successive ringing cycles appear at closer range, diminished amplitude helps maintain constant sensitivity.
Additional methods of radiating a ringdown waveform that provide enhanced compatibility with U.S. Federal Communication Commission regulations include 1) shock extiting a tuned circuit or bandpass filter with a voltage impulse/step, or 2) using a voltage impuise/step to modulate an oscillator. The first case is similar to selecting a harmonic of a frequency comb generator, where the frequency comb generator is represented by the impulse/step generator 34 in Figure I and the tuned circuit/bandpass filter 35 is an element inserted between the impulse/step generator 34 and the transmit antenna 36. The finite Q
or damping factor of the tuned circuit/bandpass filter leads to a damped sinusoidal waveform at each repetition. This damped waveform can then be .applied to either a resonant or non-resonant antenna 36.
The second ringdown method involves inserting a modulated oscillator between the step generator 34 and the antenna 36.
Figure 12A shows a modulated Colpitts ItF oscillator circuit that generates a ring-down waveform. Colpitts oscillators are well-known in rcrrtJS9aro3s9i "'°~~ 2160352 -lo-the art. However, this oscillator differs in its modulation method. The Colpitts oscillator 80 is driven by a CMOS logic inverter 82 through a modulation envelope shaping network 84, which includes capacitor 83 and series resistor 85. The shaping network 84 resistor-capacitor component values can be adjusted to provide nearly arbitrary effective damping factors, ranging from a Q of <1 (less than one oscillation cycle) to nearly infinite (steady oscillation). In operation, a negative-going logic transition from the CMOS inverter couples through the shaping network and biases the Coipitts oscillator transistor Ql on, and the oscillator generates a limited number of cycles of decreasing amplitude in correspondence to the decaying drive current provided by shaping network. A step recovery diode 86 and a bias resistor 88 are included to sharpen the drive from the CMOS inverter to provide a rapid start up drive to the Colpitts oscillator, resulting in the lack of an oscillation build-up time as evidenced by the oscillator output data in Figure 12B. If the oscillator has a slow build-up time, the radar range boundary will not be sharp. Transistor QI is a Motorola MMBR920L, the logic inverter is a Texas Instruments 74HC04 and the step recovery diode is a common computer diode type 1N4148.
The preferred damping factor is that which tends to maintain constant motion sensitivity within the range gate-typically 10-100 cycles to damp to the 37% point. The modulation envelope may be set to other than a damped sinusoid, but would be less preferred-except when the shape of the modulation envelope is used to help control the radiated spectrum for emission compatibility with regulatory agency rules.
The invention further includes randomly or pseudo-randomly dithered PRI operation. Figure 8a shows the L1WB emission spectrum when the PRI is steady, or is not dithered. It consists of spectral lines located at harmonics of the pulse repetition frequency (PRF). The envelope formed by the spectral lines is identical in shape to the spectrum produced by a single impulse. (The tall spikes are local TV
stations. ) If either random noise or code-generated pseudo-random PRI modulation, or dither, is added, as shown in Figure 8b, the emission spectrum can be spread to resemble the shape of a single impulse. Since the energy that was concentrated in individual lines is spread out, the w0 94124579 - PCT/US94103892 peak amplitude of the spectrum is reduced. Interference to conventional receivers is reduced accordingly, and resembles thermal noise.
PRI dithering affects the pulse repetition interval only, and not the pulse~cho delay time. While most commercial sampling circuits do not tolerate PRI dither, the receiver circuits used in this invention have excellent independence from PRI variations.
A high level of pulse integration, e.g.,10,000 pulses, averages out interference in the receiver, and is thus a form of time domain tuning, since it accomplishes in the time domain what tuned circuits accomplish in the frequency domain. However, if an interfering signal has a frequency that is close to a multiple of the radar PRF, beat frequencies can form that appear in the averaged signal, (although this has not been observed in practice). By applying PRI dither, the same amount of averaging occurs, but there is no steady PRF with which to form beat frequencies. PRI dither is not per se unique, but is utilized here in LTWB motion sensors.
According to the invention, the noise spectrum should lie above the LJWB detection bandwidth. This reduces or eliminates any residual dither noise appearing at the UWB detector output, and eases the noise rejection requirements imposed on the UWB detector.
The invention further provides absolute velocity measurement using dual range motion sensing. In automotive and other applications, motion- sensing plus velocity measurement is desirable. Figure 9 shows a dual detection shell scheme which is-based on either of two methods described below to project two detection shells.
As the target 62 traverses the shells 64 and 66 at Rl and R2, motion signals are generated which are detected by LJWB motion sensor 68. The time difference between the detection events stemming from R1 and R2 can be used to determine radial velocity. The dual range principles can be extended to more than two shells or ranges.
One dual detection scheme is time multiplexed dual range operation Figure 10 depicts the scheme of Figure 1 with a time multiplexed range circuit added. A squarewave oscillator 70 runs at a slower rate than the PRF, e.g., at 0.5 PRF,-so the radar alternately ranges at Rl for a period and then R2 for a period. As the detection range is alternated, an analog switch 72 is toggled in synchronism, such that the two range signals from the UWB detector are routed to separate 216 0 3 ~ 2 ~'1US94I03g92. ' integrators and motion detection circuits 74a~. The remaining components are the same as in Figure 1.
The squarewave period is much shorter than the shortest traverse time associated with Rl and R2. In practice, Rl and R2 may differ by one foot, and for the fastest automotive environment, the Rl-' R2 traversal would be several milliseconds, -much longer than the ~l~.s period of the squarewave oscillator.
Thus, with the addition of a small amount of circuitry, velocity can be measured. This feature does not require additional antennas. Unlike Doppler techniques, very low velocities .can be measured.
The other dual detection scheme is based on dual receive channels with a delay inserted into one channel. Figure 11 depicts a dual shell velocity measurement scheme using the basic motion detector of Figure 1 with an additional complete receiver channel 30b added. The second receiver 40b senses at a different range by having a cable delay 76 inserted in its antenna feedline. Alternately, a delay 78 can be inserted in the strobe line, e.g. in line 30a to receiver 40a. The remaining components are similar to Figures 1 and 10.
This system requires an additional antenna and a complete receiver, and thus is not preferred over the time multiplexed dual range system.
Unique features of UWB motion sensors are: excellent materials penetration; a sharply bounded,-adjustable active range; low cost; multi-sensor operation; and potential for single chip implementation. This array of features will enable many new applications, the range of which is limited mainly by one's imagination.
A few of the more prominent applications are the following:
Security Systems: UWB motion sensors may be placed behind walls, above ceilings, and below floors. One possible home installation would place UWB motion sensors above each room in the house and have their detection ranges set to six feet. At that range, the detection shell would reach down to a level that detects people, but would exclude detection of pets near the floor. In one test of the 100ps motion sensor of Figure 5, it was pointed through a wall into a hallway, and the range was set to span most of the width of the hallway. if a person hugged the far wall of the hallway, detection could be evaded, but an unknowing person would always be detected.
The area in front of a garage door can be protected by placing a UWB sensor inside the garage where it would be unseen by burglars, and where installation is simplified.
A single UWB VHF sensor may be placed in the center of a home and set to a detection range that projects an invisible detection shell around the entire house, providing complete home protection from a single, low-cost sensor. This concept has been successfully tested using the system of Figure 6.
For police work, UWB sensors can be discretely placed outside rooms that are to be monitored for activity. Using the battery powered UWB VHF radar of Figure 6, the sensitivity could be set so high that the slightest motion of a person in an adjacent room is detected. It does not appear possible for a living person to remain still enough to not set it off.
Novel Home Uses: UWB sensors can be built into junction boxes for use as rnncealed light switches and door openers. Homes of the future may have an invisible region near a wall where a hand can be waved to turn a light on. Doorways may be monitored by concealed UWB sensors to open them and turn lights on. UWB sensors may also help the handicapped.
Intelligent Appliances: With their unique ability to operate through plastic panels and to operate at close range, UWB sensors will find use in intelligent appliances that sense the presence of a person, or a person's hand, and respond accordingly. Lights can be turned on, doors can be opened, machines can be turned off for safety or rnnvenience, ovens can be deactivated, etc.
Life Detector For Disaster Work: Buried earthquake and avalanche victims may be located with highly sensitive UWB detectors.
The superior penetration capability of UWB radar, as well as excellent close-range operation and high sensitivity will enhance prior work using FM-CW radar. The UWB VHF radar of Figure 6 has detected respiration and possibly heartbeats at a 10 foot range.
. Medical Applications: The 100ps UWB radar of Figure 5 has detected heart beats and arterial pulses at near-zero range (surface contact). Although most of the detected signal may be due to skin w0 9anas~g _ 216 0 3 ~ 2 pcrms9a~o~s9i motion, there appears to be a deeper component. The medical significance is not known at this time. UWB radiation levels are well below the OSFiA limit for contiriuous exposure to aucrowaves.
Automotive Collision Sensor: Most of the radar community has focused on millimeter-wave (MMW j radars for - automotive use. Current cost projections for these radars are $500 or more. Some of these radars are very microphonic, since the MMW-radar wavelengths and mechanical vibrations are of similar dimensions.
Further, MMW radars will require windshield wipers due to their inability to penetrate water, mud and snow rover. MMW radar proponents overlook the fundamental fact that radar works best when the radar wavelength is on the same order as the target dimensions.
Thus, one or two meter wavelength VHF radar would be most appropriate for sensing automobiles.
UWB VHF radar antennas may consist of elementary wire dipoles embedded in plastic body sections or embedded in windows.
Although the overall dipole length should be on the order of 0.5 -1.0 meters, considerably shorter dipoles will also work since the limited detection range and large radar cross section of cars permits operation with high system losses.
Detection ranges from 1 to 10 feet are practical with omni-directional antennas. Using antennas embedded in the tail light and parking light lenses, detection shells can be projected to rover the rear, sides and front of the vehicle. These antennas may be connected to a central UWB module using low cost coaxial cables. The cost of the UWB
module could be on the order of $10. Triangulation might eventually be used to achieve sharply-controlled synthetic beamwidths.
UWB motion sensing offers three levels of alarm discrimination: radar cross section, or object size; precise detection range; and velocity measurement. All of these discriminants may easily be scaled to match vehicle speed.
Changes and modifications in the specifically described embodiments can be carried out without departing from the scope of the invention which is intended to be limited only by the scope of the claims.
Figure 12A is a schematic diagram of a modulated Colpitts RF oscillator circuit.
Figure 12B is an output signal from the circuit of Figure 12A.
pETAILED DESCRIPTTON OF THE PREFERRED F1~ODIMENTS
Referring to Figure 1, a free-running oscillator (PRI
generator) 20 generates the radar pulse repetition interval (PR'n.
Typically, this interval is lus. A noise generator 22 is connected to the PRI generator 20 to introduce a random variation to the PRI, for purposes to be described below. The output of the PRI generator 20 drives two delay means, a fixed reference delay means 24 in the transmit path 26, and an adjustable delay means 28 in the receive (gating pulse) path 30. Delay means 28 is adjusted by range adjustment means 32.
The reference delay means 24 is generally set to match the minimum delay in the receive path 30, and may also be set to account . for delays in the antenna feed lines, etc. The output of the reference delay means 24 drives an impulse (or step) generator 34 which provides the transmit pulse. If PRI generator 20 or reference delay means 24 produce a pulse with sufficiently fast rise time, then impulse (or step) generator 34 may be omitted. Otherwise, generator 34 is used to generate a suitable transmit pulse. The transmit pulse typically resembles a Gaussian shaped voltage pulse. In general, it is not a modulated RF
pulse. The UWB radar differs from conventional radar in that no carrier frequency is used. Rather, a sequence of individual poises, spaced by the PRI, is applied directly to the antenna.
The transmit pulse is directly radiated by the transmit antenna 36. There are several UWB antennas in common use, the most common of which is the tapered slot antenna, also known as an endfire antenna. In preferred embodiments, both simple wire dipoles and broader band 'bow-tie" dipoles are used. Due to their resonant nature, ringing is produced in the emitted radiation, but this effect is put to use, as will be described below.
Since many antennas exhibit increasing gain with increasing frequency, a step input applied to the transmit.antenna will result in the radiation of the derivative of the step, i.e., an impulse. In the embodiments of Figures 5 and 6, a voltage step is applied to the transmit antenna. Both the transmit and -receive antenna feedline may contain spectrum limiting or shaping filters for various purposes known to those skilled in the art.
The receive antenna 38 is connected to a UWB detector {receiver or sampler) 40, which is described in United States Patent No.
, 3 4 5 , 4 71 ~. The UWB detector may also be a wideband sampling circuit, such as those incorporated by Tektronix, Inc. and Hewlett-Packard, Inc. in their standard sampling oscilloscopes. The samp3er 40 is gated or strobed by. the output of the adjustable delay 28 through impulse (or step) generator 42, thus causing the sampler 40 to sample a point in space corresponding to the two-way echo time to the target 44. Again, impulse/step generator 42 may be omitted if the adjustable delay pulse has sufficiently short risetime. ~ ' The output of the IJVVB detector 40 is averaged in an integrator 46 with a time constant that is substantially longer than the PRI of the radar, typically lOms in a motion sensor. At a PRI of Tits,. .
10,000 pulses are averaged. This average value represents the sum of the radar reflections and other radar clutter, such as direct antenna to antenna coupling., The method can be-implernented by averaging two or more pulses: However, preferably a- large number, i.e. 1,000 to 10,000 pulses, vrrill be averaged. The transmitted pulses typically have a pulse width of about 5ns or less, and more preferably about lns or less. The PIZI
typically is in the range of 100ns to 100ms.
If the radar reflectivity changes at the range being sampled, the average will change, and this change is sensed by the differentiator 48. The output of the differentiator 48 triggers a rnmparator circuit 50, which in turn can activate an alarm. Comparator 50 compares the . output of differentiator 48 to a preset Vref. The sensitivity is controlled by Vref.
For simplicity, this invention uses an analog integrator and differentiator. A digital equivalent may be used at added complexity. In linear systems, the order of the integrator and differentiator may be interchanged. Further, the cascaded integration and differentiation wo 9anas~9 216 0 3 5 2 rcr~s9aio~s92 process resembles a bandpass filter in the frequency domain, and so a bandpass filter 52 maybe used for this combined function. Typical filter constants are: low frequency corner at 1Hz and high frequency come: at lOHz, for motion sensing of people.
The UWB pulse~cho system 54 typically operates at a constant sampling delay, or at a constant range, as depicted in Figure 2.
Due to the short impulse emitted, an effective spherical shell 56 is projected in space. The thickness of the shell is directly related to the sampling pulse width, which is generally set to be equal to the transmit pulse width T. The constant range shell then has a thickness of cT/2 where c is the pulse velocity.
Figures 3a-d show data obtained from the UWB radar of Figure 5. The horizontal scales are a slow time axis, corresponding to a 2 second time lapse. The vertical scale is the output from the UWB
detector-integrator-differentiator. In Figures 3a-d, a human hand is inserted into and then removed from the shell W thin the two second time scale, and the resulting signals are indicated for several ranges (1 ft.
in Figure 3a, 4 ft. in Figure 3b,15 in. in Figures 3c-d), and with several materials (6 in. of text books in Figure 3c, 2 in. of concrete in Figure 3d) between the radar and the target. Both insertion and removal of the hand are clearly shown.
Figure 4 shows a differential UWB receiver designed for use in UWB radar motion detector. A broadband dipole antenna 58 is .
connected to a tvrristed pair transmission line 60. Each wire of line pair 60 is rnnnected through a capacitor C1 or C2 and series resistor Rl or R2 to the positive input of an operational amplifier A1 or A2. The junctions between Cl-Rl and C2 R2 are connected to a pair of diodes Dl, D2 whose anodes are connected to the junctions and whose cathodes are connected together. A gating pulse is applied to the common cathode junction between Dl-D2. The gating pulse line may indude a capacitor Cs. The input line pair 60 and gating pulse input line are all terminated in resistors RT. The positive inputs of Al, A2 are also connected through resistors R3, R4 respectively to a + Bias voltage. The positive inputs of Al, A2 are also connected through capacitors C3, C4 to ground.
C3 and C4 can be omitted if there is sufficient input capacitance on A1, A2, or if RF rejection is not necessary or desired: The output of A1 is connected through C5 and R5 to the negative input of operational _7_ amplifier A3 and the output of AZ is connected to the positive input of A3. The output of A3 is fed back to the negative input of A3 through .
capacitor C6 and parallel variable resistor R6. Resistor R6 is adjusted to control sensitivity. The negative inputs of A1, A2 are connected together through C7 and R7 and are connected to the output of Al, A2 through C8 and parallel R8.
In an illustrative embodiment Cl=C2=22pF, RI=R2=lOK, RT=68 ohm, DI and D2 are M-Pulse MP2612 diodes, the gate pulse is -8V
with 200ps edge and 1Ns PRI generated by Metellics step recovery diode MMD 805-828 input through a 0.5 pF capacitor, R3=R4=IOM, +Bias=+5V, C3~4~.01itF, A1 A3 are TLfl74 op amps, C5 =2201.tF, R5=1K, C6~.2NF, R6=I00K (variable), C7=4.71tF, R7=47K, C8~300pF, R8 = 2.2M. If C3, C4 are omitted, then Cl=C2=O.O1N.F.
Figure S is a schematic of a micropower UWB radar motion sensor. A series of CMOS logic gates (labeled Il) form the PRI generator (33kHz oscillator) 21, which is connected through buffer gates (IZ) to the delay circuits 23ab and the impulse generators 25ab. Noise generator 19 is connected to oscillator 21. The delay means 23a is just the wire (i.e. no delay), while the delay means 23b is formed of the resistors associated with. switch S. The impulses are finally generated by step recovery diodes (SRD), supplied by Metellics Corp. of Sunnyvale, CA and specified to produce Imps transitions or faster. The transmit (T'~ and receiver (R) antennas are 6" bow-tie shaped dipoles or 3" wire monopoles. The UWB receiver 27 formed of op amps (I3) is of the type shown in Figure 4 and contains the integrator and differentiator in the form of various capacitors associated with the circuit. The switch S in the gating pulse path and in the UWB receiver is used to select the range (6' or 12'). An alarm circuit 29 is comprised of op amps I4, and includes a bipolar comparator and a driver circuit to sound an alarm after detection. The IC's are Il=CD4069, I2 74HC04, I3=TLC27L4, I4=TLC27L2. Not shown are a +3V voltage regulator and +6V penlight batteries. Because of the low duty cycle and small power consumption, the batteries last for several years in continuous operation.
Figure 6 shows a VIA security alarm circuit, operating at a transmit pulse width of 2ns. The waveform that is applied to the .18"
dipole antenna 31 is essentially a voltage step that is effectively differentiated, with ringing, by the antenna. The PRI generator {100 kHz 2160352 ~ ' PCTlUS94~03892 _g_ oscillator) 21, and buffers in the transmit and receive (strobe) paths are formed by CMOS IC's h and I2, which are 74HC04 inventors. This IC
costs less than $0.50 and generates stable, fitter-free delays trorn ~.ero to 200ns. Delay means 23a provides no delay, while delay means 23b is formed of pofientiometer R The impulse generators 25a~ include transistors Ql=2N5I09 and Q2=2N2369. Noise generator 19 is connected to oscillator 21. The two halves Slab of a dipole antenna are connected to the inputs of UWB receiver 27 which drives alarm circuit 29. The IC's are I3 TLC27L4 and I4=TLC271r2 op amps. The Schottky diodes D are 1N5711. Range delay adjustment is provided by a simple potentiometer R in the strobe line. This circuit is similar to Figure 5. It runs on batteries and its antennas are one meter in length rather than 6".
The invention is thus based on RCS (radar cross section) averaging at a fixed range cell using averaging circuits, plus averaged RCS change detection A fixed range is stared at, and a large number of return pulses are averaged. Changes in the average are then sensed as motion.
The invention also includes RCS averaging across a range sweep using averaging, plus averaged RCS change detection. Virtually _ all pulse-echo radars sweep the adjustable delay, or range delay, across a span while averaging a relatively small number of pulses, so individual "blips" may show up. In this invention, the averaging time constant can be set to be larger than the range scan Lane such that the entire sweep is averaged. Changes in this average represent motion somewhere within the range sweep.
Although individual "blips", or targets at particular ranges are diminished by the averaging process, noise levels are equally reduced by the averaging process, so the signal-to-noise ratio for changes in the blip remains the same. UWB reflections off people are a highly variable function of aspect angle, so a person moving within the averaged range sweep will produce a detectable fluctuation. This sweep averaging technique is intended as a simplification to UWB motion sensor hardware.
The invention also includes an antenna ringdown method of motion detection across a range span, using averaging circuits, plus averaged RCS change detection. Figure 7 shows typical antenna-ringdown produced'by a transmit/receive dipole pair when excited by a _216032 WO 9411,4579 PCT/US94103892 fast rising voltage step. UWB motion sensors operate primarily at a detection range corresponding to the time of flight of the leading edge of the transmitted pulse. Ringing that is trailing the leading edge appears later in time, while in space, ringing appears at a range closer to the radar, for a fixed sampling delay. Thus, for a given range delay setting, ringing pulses generate an outermost detection shell corresponding to the leading pulse, and successive inner detection shells located by the periodicity of the ringing.
The advantage to ringing is that it generates an effective range sweep since multiple ranges become active for motion sensing.
Yet, range sweeping hardware is eliminated and the use of simple dipole antennas is allowed.
Another advantage to this technique, or to an averaged range sweep, is that if a target manages to evade the outer detection shell, the inner shells may still be activated. This situation occurs when the target echo from the outer range shell is too small to be detected. It also prevents a person from walking up to a UWB motion detector without setting it off.
As the antenna rings down, ringing amplitude decreases.
-Since successive ringing cycles appear at closer range, diminished amplitude helps maintain constant sensitivity.
Additional methods of radiating a ringdown waveform that provide enhanced compatibility with U.S. Federal Communication Commission regulations include 1) shock extiting a tuned circuit or bandpass filter with a voltage impulse/step, or 2) using a voltage impuise/step to modulate an oscillator. The first case is similar to selecting a harmonic of a frequency comb generator, where the frequency comb generator is represented by the impulse/step generator 34 in Figure I and the tuned circuit/bandpass filter 35 is an element inserted between the impulse/step generator 34 and the transmit antenna 36. The finite Q
or damping factor of the tuned circuit/bandpass filter leads to a damped sinusoidal waveform at each repetition. This damped waveform can then be .applied to either a resonant or non-resonant antenna 36.
The second ringdown method involves inserting a modulated oscillator between the step generator 34 and the antenna 36.
Figure 12A shows a modulated Colpitts ItF oscillator circuit that generates a ring-down waveform. Colpitts oscillators are well-known in rcrrtJS9aro3s9i "'°~~ 2160352 -lo-the art. However, this oscillator differs in its modulation method. The Colpitts oscillator 80 is driven by a CMOS logic inverter 82 through a modulation envelope shaping network 84, which includes capacitor 83 and series resistor 85. The shaping network 84 resistor-capacitor component values can be adjusted to provide nearly arbitrary effective damping factors, ranging from a Q of <1 (less than one oscillation cycle) to nearly infinite (steady oscillation). In operation, a negative-going logic transition from the CMOS inverter couples through the shaping network and biases the Coipitts oscillator transistor Ql on, and the oscillator generates a limited number of cycles of decreasing amplitude in correspondence to the decaying drive current provided by shaping network. A step recovery diode 86 and a bias resistor 88 are included to sharpen the drive from the CMOS inverter to provide a rapid start up drive to the Colpitts oscillator, resulting in the lack of an oscillation build-up time as evidenced by the oscillator output data in Figure 12B. If the oscillator has a slow build-up time, the radar range boundary will not be sharp. Transistor QI is a Motorola MMBR920L, the logic inverter is a Texas Instruments 74HC04 and the step recovery diode is a common computer diode type 1N4148.
The preferred damping factor is that which tends to maintain constant motion sensitivity within the range gate-typically 10-100 cycles to damp to the 37% point. The modulation envelope may be set to other than a damped sinusoid, but would be less preferred-except when the shape of the modulation envelope is used to help control the radiated spectrum for emission compatibility with regulatory agency rules.
The invention further includes randomly or pseudo-randomly dithered PRI operation. Figure 8a shows the L1WB emission spectrum when the PRI is steady, or is not dithered. It consists of spectral lines located at harmonics of the pulse repetition frequency (PRF). The envelope formed by the spectral lines is identical in shape to the spectrum produced by a single impulse. (The tall spikes are local TV
stations. ) If either random noise or code-generated pseudo-random PRI modulation, or dither, is added, as shown in Figure 8b, the emission spectrum can be spread to resemble the shape of a single impulse. Since the energy that was concentrated in individual lines is spread out, the w0 94124579 - PCT/US94103892 peak amplitude of the spectrum is reduced. Interference to conventional receivers is reduced accordingly, and resembles thermal noise.
PRI dithering affects the pulse repetition interval only, and not the pulse~cho delay time. While most commercial sampling circuits do not tolerate PRI dither, the receiver circuits used in this invention have excellent independence from PRI variations.
A high level of pulse integration, e.g.,10,000 pulses, averages out interference in the receiver, and is thus a form of time domain tuning, since it accomplishes in the time domain what tuned circuits accomplish in the frequency domain. However, if an interfering signal has a frequency that is close to a multiple of the radar PRF, beat frequencies can form that appear in the averaged signal, (although this has not been observed in practice). By applying PRI dither, the same amount of averaging occurs, but there is no steady PRF with which to form beat frequencies. PRI dither is not per se unique, but is utilized here in LTWB motion sensors.
According to the invention, the noise spectrum should lie above the LJWB detection bandwidth. This reduces or eliminates any residual dither noise appearing at the UWB detector output, and eases the noise rejection requirements imposed on the UWB detector.
The invention further provides absolute velocity measurement using dual range motion sensing. In automotive and other applications, motion- sensing plus velocity measurement is desirable. Figure 9 shows a dual detection shell scheme which is-based on either of two methods described below to project two detection shells.
As the target 62 traverses the shells 64 and 66 at Rl and R2, motion signals are generated which are detected by LJWB motion sensor 68. The time difference between the detection events stemming from R1 and R2 can be used to determine radial velocity. The dual range principles can be extended to more than two shells or ranges.
One dual detection scheme is time multiplexed dual range operation Figure 10 depicts the scheme of Figure 1 with a time multiplexed range circuit added. A squarewave oscillator 70 runs at a slower rate than the PRF, e.g., at 0.5 PRF,-so the radar alternately ranges at Rl for a period and then R2 for a period. As the detection range is alternated, an analog switch 72 is toggled in synchronism, such that the two range signals from the UWB detector are routed to separate 216 0 3 ~ 2 ~'1US94I03g92. ' integrators and motion detection circuits 74a~. The remaining components are the same as in Figure 1.
The squarewave period is much shorter than the shortest traverse time associated with Rl and R2. In practice, Rl and R2 may differ by one foot, and for the fastest automotive environment, the Rl-' R2 traversal would be several milliseconds, -much longer than the ~l~.s period of the squarewave oscillator.
Thus, with the addition of a small amount of circuitry, velocity can be measured. This feature does not require additional antennas. Unlike Doppler techniques, very low velocities .can be measured.
The other dual detection scheme is based on dual receive channels with a delay inserted into one channel. Figure 11 depicts a dual shell velocity measurement scheme using the basic motion detector of Figure 1 with an additional complete receiver channel 30b added. The second receiver 40b senses at a different range by having a cable delay 76 inserted in its antenna feedline. Alternately, a delay 78 can be inserted in the strobe line, e.g. in line 30a to receiver 40a. The remaining components are similar to Figures 1 and 10.
This system requires an additional antenna and a complete receiver, and thus is not preferred over the time multiplexed dual range system.
Unique features of UWB motion sensors are: excellent materials penetration; a sharply bounded,-adjustable active range; low cost; multi-sensor operation; and potential for single chip implementation. This array of features will enable many new applications, the range of which is limited mainly by one's imagination.
A few of the more prominent applications are the following:
Security Systems: UWB motion sensors may be placed behind walls, above ceilings, and below floors. One possible home installation would place UWB motion sensors above each room in the house and have their detection ranges set to six feet. At that range, the detection shell would reach down to a level that detects people, but would exclude detection of pets near the floor. In one test of the 100ps motion sensor of Figure 5, it was pointed through a wall into a hallway, and the range was set to span most of the width of the hallway. if a person hugged the far wall of the hallway, detection could be evaded, but an unknowing person would always be detected.
The area in front of a garage door can be protected by placing a UWB sensor inside the garage where it would be unseen by burglars, and where installation is simplified.
A single UWB VHF sensor may be placed in the center of a home and set to a detection range that projects an invisible detection shell around the entire house, providing complete home protection from a single, low-cost sensor. This concept has been successfully tested using the system of Figure 6.
For police work, UWB sensors can be discretely placed outside rooms that are to be monitored for activity. Using the battery powered UWB VHF radar of Figure 6, the sensitivity could be set so high that the slightest motion of a person in an adjacent room is detected. It does not appear possible for a living person to remain still enough to not set it off.
Novel Home Uses: UWB sensors can be built into junction boxes for use as rnncealed light switches and door openers. Homes of the future may have an invisible region near a wall where a hand can be waved to turn a light on. Doorways may be monitored by concealed UWB sensors to open them and turn lights on. UWB sensors may also help the handicapped.
Intelligent Appliances: With their unique ability to operate through plastic panels and to operate at close range, UWB sensors will find use in intelligent appliances that sense the presence of a person, or a person's hand, and respond accordingly. Lights can be turned on, doors can be opened, machines can be turned off for safety or rnnvenience, ovens can be deactivated, etc.
Life Detector For Disaster Work: Buried earthquake and avalanche victims may be located with highly sensitive UWB detectors.
The superior penetration capability of UWB radar, as well as excellent close-range operation and high sensitivity will enhance prior work using FM-CW radar. The UWB VHF radar of Figure 6 has detected respiration and possibly heartbeats at a 10 foot range.
. Medical Applications: The 100ps UWB radar of Figure 5 has detected heart beats and arterial pulses at near-zero range (surface contact). Although most of the detected signal may be due to skin w0 9anas~g _ 216 0 3 ~ 2 pcrms9a~o~s9i motion, there appears to be a deeper component. The medical significance is not known at this time. UWB radiation levels are well below the OSFiA limit for contiriuous exposure to aucrowaves.
Automotive Collision Sensor: Most of the radar community has focused on millimeter-wave (MMW j radars for - automotive use. Current cost projections for these radars are $500 or more. Some of these radars are very microphonic, since the MMW-radar wavelengths and mechanical vibrations are of similar dimensions.
Further, MMW radars will require windshield wipers due to their inability to penetrate water, mud and snow rover. MMW radar proponents overlook the fundamental fact that radar works best when the radar wavelength is on the same order as the target dimensions.
Thus, one or two meter wavelength VHF radar would be most appropriate for sensing automobiles.
UWB VHF radar antennas may consist of elementary wire dipoles embedded in plastic body sections or embedded in windows.
Although the overall dipole length should be on the order of 0.5 -1.0 meters, considerably shorter dipoles will also work since the limited detection range and large radar cross section of cars permits operation with high system losses.
Detection ranges from 1 to 10 feet are practical with omni-directional antennas. Using antennas embedded in the tail light and parking light lenses, detection shells can be projected to rover the rear, sides and front of the vehicle. These antennas may be connected to a central UWB module using low cost coaxial cables. The cost of the UWB
module could be on the order of $10. Triangulation might eventually be used to achieve sharply-controlled synthetic beamwidths.
UWB motion sensing offers three levels of alarm discrimination: radar cross section, or object size; precise detection range; and velocity measurement. All of these discriminants may easily be scaled to match vehicle speed.
Changes and modifications in the specifically described embodiments can be carried out without departing from the scope of the invention which is intended to be limited only by the scope of the claims.
Claims (15)
1. A method of using ultra-wideband (UWB) radar pulses, comprising the steps of:
transmitting said UWB radar pulses;
receiving and processing reflected UWB radar pulses by detecting said reflected UWB
radar pulses from a predetermined range and by producing a baseband detection output signal indicative of a plurality of said detected pulses;
integrating said baseband detection output signal, thereby producing a baseband average output signal corresponding to an average of said plurality of said detected pulses; and differentiating baseband average output signals produced at different times, thereby detecting motion.
transmitting said UWB radar pulses;
receiving and processing reflected UWB radar pulses by detecting said reflected UWB
radar pulses from a predetermined range and by producing a baseband detection output signal indicative of a plurality of said detected pulses;
integrating said baseband detection output signal, thereby producing a baseband average output signal corresponding to an average of said plurality of said detected pulses; and differentiating baseband average output signals produced at different times, thereby detecting motion.
2. A method of using ultra-wideband (UWB) radar pulses, comprising the steps of:
transmitting said UWB radar pulses;
receiving and processing reflected UWB radar pulses by detecting said reflected UWB
radar pulses from a predetermined range and by producing a baseband of detection output signal indicative of a plurality of said detected pulses;
differentiating baseband detection output signals produced at different times, thereby producing a baseband differentiation output signal; and integrating said baseband differentiation output signal, thereby detecting motion.
transmitting said UWB radar pulses;
receiving and processing reflected UWB radar pulses by detecting said reflected UWB
radar pulses from a predetermined range and by producing a baseband of detection output signal indicative of a plurality of said detected pulses;
differentiating baseband detection output signals produced at different times, thereby producing a baseband differentiation output signal; and integrating said baseband differentiation output signal, thereby detecting motion.
3. A method of using ultra-wideband (UWB) radar pulses, comprising the steps of:
transmitting said UWB radar pulses; and receiving and processing reflected UWB radar pulses by detecting said reflected UWB
radar pulses from a predetermined range and by producing a baseband detection output signal indicative of a plurality of said pulses, wherein the step of producing a detection output signal comprises a step of integrating said reflected UWB radar pulses, said detection output signal corresponding to an average of said plurality of said reflected pulses, and in that said method further comprises the steps of:
integrating said baseband detection output signal, thereby producing a baseband average output signal corresponding to a further average of said plurality of said reflected pulses; and differentiating baseband average output signals produced at different times, thereby detecting motion.
transmitting said UWB radar pulses; and receiving and processing reflected UWB radar pulses by detecting said reflected UWB
radar pulses from a predetermined range and by producing a baseband detection output signal indicative of a plurality of said pulses, wherein the step of producing a detection output signal comprises a step of integrating said reflected UWB radar pulses, said detection output signal corresponding to an average of said plurality of said reflected pulses, and in that said method further comprises the steps of:
integrating said baseband detection output signal, thereby producing a baseband average output signal corresponding to a further average of said plurality of said reflected pulses; and differentiating baseband average output signals produced at different times, thereby detecting motion.
4. A method of using ultra-wideband (UWB) radar pulses, comprising the steps of:
transmitting said UWB radar pulses; and receiving and processing reflected UWB radar pulses by detecting said reflected UWB
radar pulses from a predetermined range and by producing a baseband detection output signal indicative of a plurality of said pulses, wherein the step of producing a detection output signal comprises a step of integrating said reflected UWB radar pulses, said detection output signal corresponding to an average of said plurality of said reflected pulses, and in that said method further comprises the steps of:
differentiating baseband detection output signals produced at different times, thereby producing a baseband differentiation output signal; and integrating said baseband differentiation output signal, thereby detecting motion.
transmitting said UWB radar pulses; and receiving and processing reflected UWB radar pulses by detecting said reflected UWB
radar pulses from a predetermined range and by producing a baseband detection output signal indicative of a plurality of said pulses, wherein the step of producing a detection output signal comprises a step of integrating said reflected UWB radar pulses, said detection output signal corresponding to an average of said plurality of said reflected pulses, and in that said method further comprises the steps of:
differentiating baseband detection output signals produced at different times, thereby producing a baseband differentiation output signal; and integrating said baseband differentiation output signal, thereby detecting motion.
5. The method of any one of claims 1 to 4, wherein the step of detecting reflected pulses from a predetermined range is performed by opening a sampling gate at a fixed delay after emission of a transmit pulse.
6. The method of any one of claims 1 to 4, further comprising adjusting said predetermined range.
7. The method of any one of claims 1 to 4, further comprising integrating about 1,000 to 10,000 pulses.
8. The method of any one of claims 1 to 4, further comprising dithering pulse repetition frequency of transmitted pulses.
9. The method of any one of claims 1 to 4, further comprising transmitting UWB
radar pulses with pulse widths of less than 5 ns.
radar pulses with pulse widths of less than 5 ns.
10. The method of claim 9, further comprising transmitting UWB radar pulses with pulse widths of less than 1 ns.
11. The method of any one of claims 1 to 4, further comprising measuring signals from two different ranges and determining velocity from a time difference between signals from said two different ranges.
12. The method of any one of claims 1 to 4, further comprising detecting reflected pulses caused by antenna ringdown.
13. The method of any one of claims 1 to 4, further comprising forming the transmitted UWB radar pulses by shock exciting a turned circuit or bandpass filter.
14. The method of any one of claims 1 to 4, further comprising forming the transmitted UWB radar pulse by modulating an oscillator.
15. The method of any one of claims 1 to 4, wherein the radar pulses are transmitted without a carrier frequency.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CA 2503382 CA2503382C (en) | 1993-04-12 | 1994-04-08 | Ultra-wideband radar motion sensor |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US08/044,717 | 1993-04-12 | ||
US08044717 US5361070B1 (en) | 1993-04-12 | 1993-04-12 | Ultra-wideband radar motion sensor |
PCT/US1994/003892 WO1994024579A1 (en) | 1993-04-12 | 1994-04-08 | Ultra-wideband radar motion sensor |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA 2503382 Division CA2503382C (en) | 1993-04-12 | 1994-04-08 | Ultra-wideband radar motion sensor |
Publications (2)
Publication Number | Publication Date |
---|---|
CA2160352A1 CA2160352A1 (en) | 1994-10-27 |
CA2160352C true CA2160352C (en) | 2006-01-10 |
Family
ID=21933942
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA002160352A Expired - Lifetime CA2160352C (en) | 1993-04-12 | 1994-04-08 | Ultra-wideband radar motion sensor |
CA 2503382 Expired - Lifetime CA2503382C (en) | 1993-04-12 | 1994-04-08 | Ultra-wideband radar motion sensor |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA 2503382 Expired - Lifetime CA2503382C (en) | 1993-04-12 | 1994-04-08 | Ultra-wideband radar motion sensor |
Country Status (8)
Country | Link |
---|---|
US (1) | US5361070B1 (en) |
EP (2) | EP0694171B1 (en) |
JP (2) | JP3471803B2 (en) |
KR (1) | KR100322662B1 (en) |
AT (2) | ATE214853T1 (en) |
CA (2) | CA2160352C (en) |
DE (2) | DE69430195T2 (en) |
WO (1) | WO1994024579A1 (en) |
Families Citing this family (309)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
USRE41479E1 (en) | 1984-12-03 | 2010-08-10 | Time Domain Corporation | Time domain radio transmission system |
USRE39759E1 (en) | 1984-12-03 | 2007-08-07 | Time Domain Corporation | Time domain radio transmission system |
US20030016157A1 (en) * | 1984-12-03 | 2003-01-23 | Fullerton Larry W. | Time domain radio transmission system |
US6882301B2 (en) | 1986-06-03 | 2005-04-19 | Time Domain Corporation | Time domain radio transmission system |
US6078854A (en) | 1995-06-07 | 2000-06-20 | Automotive Technologies International, Inc. | Apparatus and method for adjusting a vehicle component |
US5847676A (en) * | 1992-05-28 | 1998-12-08 | Cole; Carroll Richard | Velocity detecting system |
US5774091A (en) * | 1993-04-12 | 1998-06-30 | The Regents Of The University Of California | Short range micro-power impulse radar with high resolution swept range gate with damped transmit and receive cavities |
US5523760A (en) * | 1993-04-12 | 1996-06-04 | The Regents Of The University Of California | Ultra-wideband receiver |
US5519400A (en) * | 1993-04-12 | 1996-05-21 | The Regents Of The University Of California | Phase coded, micro-power impulse radar motion sensor |
US5757320A (en) * | 1993-04-12 | 1998-05-26 | The Regents Of The University Of California | Short range, ultra-wideband radar with high resolution swept range gate |
DE4405238C2 (en) | 1994-02-18 | 1998-07-09 | Endress Hauser Gmbh Co | Arrangement for measuring the level in a container |
US5748891A (en) * | 1994-07-22 | 1998-05-05 | Aether Wire & Location | Spread spectrum localizers |
US5573012A (en) * | 1994-08-09 | 1996-11-12 | The Regents Of The University Of California | Body monitoring and imaging apparatus and method |
US5543799A (en) * | 1994-09-02 | 1996-08-06 | Zircon Corporation | Swept range gate radar system for detection of nearby objects |
US5682164A (en) * | 1994-09-06 | 1997-10-28 | The Regents Of The University Of California | Pulse homodyne field disturbance sensor |
US9443358B2 (en) | 1995-06-07 | 2016-09-13 | Automotive Vehicular Sciences LLC | Vehicle software upgrade techniques |
US6405132B1 (en) | 1997-10-22 | 2002-06-11 | Intelligent Technologies International, Inc. | Accident avoidance system |
US7770920B2 (en) | 1995-06-07 | 2010-08-10 | Automotive Technologies International, Inc. | Vehicular seats with fluid-containing weight sensing system |
US5672975A (en) | 1995-06-07 | 1997-09-30 | Rosemount Inc. | Two-wire level transmitter |
US6720920B2 (en) | 1997-10-22 | 2004-04-13 | Intelligent Technologies International Inc. | Method and arrangement for communicating between vehicles |
US7766383B2 (en) * | 1998-11-17 | 2010-08-03 | Automotive Technologies International, Inc. | Vehicular component adjustment system and method |
US5764162A (en) * | 1995-07-20 | 1998-06-09 | Union Switch & Signal Inc. | Micropower impulse radar based wheel detector |
GB2303510A (en) * | 1995-07-20 | 1997-02-19 | Union Switch & Signal Inc | Radar wheel detector |
US5905455A (en) * | 1995-08-11 | 1999-05-18 | Zircon Corporation | Dual transmitter visual display system |
US5668555A (en) * | 1995-09-01 | 1997-09-16 | Starr; Jon E. | Imaging system and apparatus |
US5841392A (en) * | 1995-10-02 | 1998-11-24 | Nikon Corporation | Pulse-echo ranging system with improved target |
GB9520487D0 (en) * | 1995-10-06 | 1995-12-06 | Cambridge Consultants | Short range electromagnetic sensor |
US6118282A (en) * | 1995-12-19 | 2000-09-12 | Endress & Hauser Gmbh & Co. | Sensor apparatus |
US5827985A (en) * | 1995-12-19 | 1998-10-27 | Endress + Hauser Gmbh + Co. | Sensor apparatus for process measurement |
US5661251A (en) * | 1995-12-19 | 1997-08-26 | Endress + Hauser Gmbh + Co. | Sensor apparatus for process measurement |
US5841666A (en) * | 1995-12-21 | 1998-11-24 | Endress + Hauser Gmbh + Co. | Processor apparatus and method for a process measurement signal |
US5884231A (en) | 1995-12-21 | 1999-03-16 | Endress & Hauser Gmbh & Co. | Processor apparatus and method for a process measurement signal |
US5805767A (en) * | 1996-01-16 | 1998-09-08 | Jouas; Gary | Electronically-controlled heater |
DE19601489C2 (en) * | 1996-01-17 | 2002-11-07 | Steinel Gmbh & Co Kg | Device for controlling a lamp |
EP0787998A3 (en) * | 1996-02-02 | 1998-05-20 | f+g megamos Sicherheitselektronik GmbH | Microwave sensor system for the monitoring of spaces |
US5729694A (en) * | 1996-02-06 | 1998-03-17 | The Regents Of The University Of California | Speech coding, reconstruction and recognition using acoustics and electromagnetic waves |
US6542857B1 (en) * | 1996-02-06 | 2003-04-01 | The Regents Of The University Of California | System and method for characterizing synthesizing and/or canceling out acoustic signals from inanimate sound sources |
US6006175A (en) * | 1996-02-06 | 1999-12-21 | The Regents Of The University Of California | Methods and apparatus for non-acoustic speech characterization and recognition |
US5752783A (en) * | 1996-02-20 | 1998-05-19 | Blaw-Knox Construction Equipment Corporation | Paver with radar screed control |
US5708377A (en) * | 1996-02-23 | 1998-01-13 | Wiltron Company | Low power dual sampler utilizing step recovery diodes (SRDS) |
US6195015B1 (en) | 1996-07-19 | 2001-02-27 | Intelligent Devices, Inc. | Electronic parking meter |
GB2318009A (en) * | 1996-10-05 | 1998-04-08 | Ford Motor Co | Ground speed measurement using impulse radar |
JPH10122861A (en) * | 1996-10-16 | 1998-05-15 | Nikon Corp | Position measuring apparatus and position measuring method using the apparatus |
US5901633A (en) * | 1996-11-27 | 1999-05-11 | Case Corporation | Method and apparatus for sensing piston position using a dipstick assembly |
US6142059A (en) * | 1996-11-27 | 2000-11-07 | Case Corporation | Method and apparatus for sensing the orientation of a mechanical actuator |
US5977778A (en) * | 1996-11-27 | 1999-11-02 | Case Corporation | Method and apparatus for sensing piston position |
US5828333A (en) * | 1997-01-21 | 1998-10-27 | Northrop Grumman Corporation | Multiple access diplex doppler radar |
US6085151A (en) * | 1998-01-20 | 2000-07-04 | Automotive Systems Laboratory, Inc. | Predictive collision sensing system |
NL1005865C1 (en) * | 1997-04-22 | 1998-10-26 | Hollandse Signaalapparaten Bv | Receiving system. |
US6008546A (en) * | 1997-05-02 | 1999-12-28 | Assembled Products Corporation | Electronic control system and collision avoidance system for an electric cart |
US7209523B1 (en) | 1997-05-16 | 2007-04-24 | Multispectral Solutions, Inc. | Ultra-wideband receiver and transmitter |
US6026125A (en) * | 1997-05-16 | 2000-02-15 | Multispectral Solutions, Inc. | Waveform adaptive ultra-wideband transmitter |
US5978749A (en) * | 1997-06-30 | 1999-11-02 | Pile Dynamics, Inc. | Pile installation recording system |
US6067673A (en) * | 1997-07-18 | 2000-05-30 | Kohler Company | Bathroom fixture using radar detector having leaky transmission line to control fluid flow |
EP0995127B1 (en) | 1997-07-18 | 2002-11-27 | Kohler Co. | Radar devices for low power applications and bathroom fixtures |
AU8404398A (en) | 1997-07-18 | 1999-02-10 | Kohler Company | Advanced touchless plumbing systems |
US6005395A (en) * | 1997-11-12 | 1999-12-21 | Case Corporation | Method and apparatus for sensing piston position |
US6700939B1 (en) | 1997-12-12 | 2004-03-02 | Xtremespectrum, Inc. | Ultra wide bandwidth spread-spectrum communications system |
US6012001A (en) * | 1997-12-30 | 2000-01-04 | Scully; Robert L. | Method and apparatus for determining aircraft-to-ground distances and descent rates during landing |
US6386055B1 (en) | 1998-01-06 | 2002-05-14 | Endress +Hauser Gmbh +Co. | Sensor apparatus for transmitting electrical pulses from a signal line into and out of a vessel to measure a process variable—in order to be more informative |
US5973637A (en) * | 1998-01-09 | 1999-10-26 | Endress + Hauser Gmbh + Co. | Partial probe mapping |
US6078280A (en) * | 1998-01-09 | 2000-06-20 | Endress + Hauser Gmbh + Co. | Periodic probe mapping |
DE19806592A1 (en) * | 1998-02-17 | 1999-09-23 | Steinel Gmbh & Co Kg | Microwave motion sensor |
US6501393B1 (en) * | 1999-09-27 | 2002-12-31 | Time Domain Corporation | System and method for using impulse radio technology to track and monitor vehicles |
US6128558A (en) * | 1998-06-09 | 2000-10-03 | Wabtec Railway Electronics, Inc. | Method and apparatus for using machine vision to detect relative locomotive position on parallel tracks |
US6377215B1 (en) | 1998-06-09 | 2002-04-23 | Wabtec Railway Electronics | Apparatus and method for detecting railroad locomotive turns by monitoring truck orientation |
US6360998B1 (en) | 1998-06-09 | 2002-03-26 | Westinghouse Air Brake Company | Method and apparatus for controlling trains by determining a direction taken by a train through a railroad switch |
US6626038B1 (en) | 1998-06-18 | 2003-09-30 | Magnetrol International Inc. | Time domain reflectometry measurement instrument |
US6417797B1 (en) | 1998-07-14 | 2002-07-09 | Cirrus Logic, Inc. | System for A multi-purpose portable imaging device and methods for using same |
US6239741B1 (en) * | 1998-07-20 | 2001-05-29 | Multispectral Solutions, Inc. | UWB dual tunnel diode detector for object detection, measurement, or avoidance |
DE19833327C2 (en) * | 1998-07-24 | 2002-03-21 | S M S | Pulse radar device |
US6208246B1 (en) | 1998-07-31 | 2001-03-27 | Wabtec Railway Electronics, Inc. | Method and apparatus for improving railcar visibility at grade crossings |
US5986579A (en) * | 1998-07-31 | 1999-11-16 | Westinghouse Air Brake Company | Method and apparatus for determining railcar order in a train |
US6273521B1 (en) | 1998-07-31 | 2001-08-14 | Westinghouse Air Brake Technologies Corporation | Electronic air brake control system for railcars |
US10240935B2 (en) | 1998-10-22 | 2019-03-26 | American Vehicular Sciences Llc | Vehicle software upgrade techniques |
US7346120B2 (en) | 1998-12-11 | 2008-03-18 | Freescale Semiconductor Inc. | Method and system for performing distance measuring and direction finding using ultrawide bandwidth transmissions |
US6559657B1 (en) | 1999-01-13 | 2003-05-06 | Endress+Hauser Gmbh+Co. | Probe mapping diagnostic methods |
US6229455B1 (en) | 1999-01-15 | 2001-05-08 | Intelligent Devices, Inc. | Vehicle-detecting unit for use with electronic parking meter |
US6191724B1 (en) * | 1999-01-28 | 2001-02-20 | Mcewan Thomas E. | Short pulse microwave transceiver |
US6279173B1 (en) | 1999-04-12 | 2001-08-28 | D2M, Inc. | Devices and methods for toilet ventilation using a radar sensor |
US6239736B1 (en) | 1999-04-21 | 2001-05-29 | Interlogix, Inc. | Range-gated radar motion detector |
US6351246B1 (en) | 1999-05-03 | 2002-02-26 | Xtremespectrum, Inc. | Planar ultra wide band antenna with integrated electronics |
JP3577239B2 (en) * | 1999-05-28 | 2004-10-13 | 三菱電機株式会社 | Radar equipment |
US6177903B1 (en) * | 1999-06-14 | 2001-01-23 | Time Domain Corporation | System and method for intrusion detection using a time domain radar array |
US7592944B2 (en) * | 1999-06-14 | 2009-09-22 | Time Domain Corporation | System and method for intrusion detection using a time domain radar array |
US6218979B1 (en) | 1999-06-14 | 2001-04-17 | Time Domain Corporation | Wide area time domain radar array |
US7649925B2 (en) * | 1999-06-14 | 2010-01-19 | Time Domain Corporation | Time transfer utilizing ultra wideband signals |
US6165135A (en) * | 1999-07-14 | 2000-12-26 | Neff; Samuel R. | System and method of interrogating implanted passive resonant-circuit devices |
US6421389B1 (en) * | 1999-07-16 | 2002-07-16 | Time Domain Corporation | Baseband signal converter for a wideband impulse radio receiver |
US6795491B2 (en) * | 1999-07-22 | 2004-09-21 | Aether Wire & Location | Spread spectrum localizers |
EP1083412A1 (en) | 1999-09-07 | 2001-03-14 | Endress + Hauser Gmbh + Co. | Device for determining a physical quantity of a fluid or a solid material |
EP1083414A1 (en) | 1999-09-11 | 2001-03-14 | Endress + Hauser GmbH + Co. | Level measuring device |
JP4655253B2 (en) * | 1999-10-19 | 2011-03-23 | 有限会社 マイクロウェーブラボ | Microwave band sampling high-frequency amplifier and transmitter / receiver using the same |
US6304798B1 (en) | 1999-11-29 | 2001-10-16 | Storage Technology Corporation | Automated data storage library with wireless robotic positioning system |
DE19961855B4 (en) * | 1999-12-22 | 2007-11-29 | Endress + Hauser Gmbh + Co. Kg | Method and device for determining the fill level of a product in a container |
US7068211B2 (en) | 2000-02-08 | 2006-06-27 | Cambridge Consultants Limited | Methods and apparatus for obtaining positional information |
US6906625B1 (en) | 2000-02-24 | 2005-06-14 | Time Domain Corporation | System and method for information assimilation and functionality control based on positioning information obtained by impulse radio techniques |
US20010037724A1 (en) | 2000-03-08 | 2001-11-08 | Schumacher Mark S. | System for controlling hydraulic actuator |
US20010037689A1 (en) | 2000-03-08 | 2001-11-08 | Krouth Terrance F. | Hydraulic actuator piston measurement apparatus and method |
JP2003526097A (en) | 2000-03-08 | 2003-09-02 | ローズマウント インコーポレイテッド | Two-way differential pressure fluid sensor |
AU2001241641A1 (en) | 2000-03-08 | 2001-09-17 | Rosemount, Inc. | Piston position measuring device |
US6340139B1 (en) | 2000-06-01 | 2002-01-22 | Labarge, Inc. | Highway grade crossing vehicle violation detector |
AU2001282867A1 (en) | 2000-08-07 | 2002-02-18 | Xtremespectrum, Inc. | Electrically small planar uwb antenna apparatus and system thereof |
WO2002041025A2 (en) * | 2000-11-20 | 2002-05-23 | Endress + Hauser Gmbh + Co. Kg | Sensor apparatus |
US6667724B2 (en) | 2001-02-26 | 2003-12-23 | Time Domain Corporation | Impulse radar antenna array and method |
US6426716B1 (en) | 2001-02-27 | 2002-07-30 | Mcewan Technologies, Llc | Modulated pulse doppler sensor |
US6612172B2 (en) * | 2001-03-05 | 2003-09-02 | Lucent Technologies Inc. | Sol-gel tube crack detection apparatus and method |
US6937639B2 (en) * | 2001-04-16 | 2005-08-30 | Time Domain Corporation | System and method for positioning pulses in time using a code that provides spectral shaping |
US6588313B2 (en) | 2001-05-16 | 2003-07-08 | Rosemont Inc. | Hydraulic piston position sensor |
US6512474B2 (en) | 2001-05-23 | 2003-01-28 | Lockhead Martin Corporation | Ultra wideband signal source |
US6456231B1 (en) | 2001-06-01 | 2002-09-24 | Mcewan Technologies, Llc | Radar sensor having a CFAR detector |
US20020189336A1 (en) * | 2001-06-15 | 2002-12-19 | Mcewan Technologies, Llc | Radar monitoring system for tires and wheels |
KR20030013744A (en) * | 2001-08-09 | 2003-02-15 | 주식회사 백금정보통신 | Wide band radar detector having a weather radio |
US7321601B2 (en) | 2001-09-26 | 2008-01-22 | General Atomics | Method and apparatus for data transfer using a time division multiple frequency scheme supplemented with polarity modulation |
WO2003028255A2 (en) * | 2001-09-26 | 2003-04-03 | General Atomics | Method and apparatus for data transfer using a time division multiple frequency scheme |
US7609608B2 (en) * | 2001-09-26 | 2009-10-27 | General Atomics | Method and apparatus for data transfer using a time division multiple frequency scheme with additional modulation |
US7236464B2 (en) * | 2001-09-26 | 2007-06-26 | General Atomics | Flexible method and apparatus for encoding and decoding signals using a time division multiple frequency scheme |
US6781470B2 (en) * | 2001-09-26 | 2004-08-24 | General Atomics | Tunable oscillator |
US7342973B2 (en) * | 2001-09-26 | 2008-03-11 | General Atomics | Method and apparatus for adapting multi-band ultra-wideband signaling to interference sources |
DE10152811A1 (en) * | 2001-10-25 | 2003-05-08 | Delphi Tech Inc | Radar protection system has signal acquisition, evaluation device sampling circuit connected to receiving antenna and driven by sampling signal from delay line subjected to transmission pulse |
WO2003042919A2 (en) | 2001-11-09 | 2003-05-22 | Pulse-Link, Inc. | Ultra-wideband imaging system |
DE10163569A1 (en) * | 2001-12-21 | 2003-11-06 | Endress & Hauser Gmbh & Co Kg | Method for determining and / or monitoring a physical or chemical process variable |
AU2003219844A1 (en) * | 2002-02-20 | 2003-09-09 | General Atomics | Flexible method and apparatus for encoding and decoding signals using a time division multiple frequency scheme |
US6753780B2 (en) * | 2002-03-15 | 2004-06-22 | Delphi Technologies, Inc. | Vehicle occupant detection system and method using radar motion sensor |
US7006583B2 (en) * | 2002-08-30 | 2006-02-28 | Intel Corporation | Method and apparatus for receiving differential ultra wideband signals |
US7061379B2 (en) | 2002-11-21 | 2006-06-13 | Kimberly-Clark Worldwide, Inc. | RFID system and method for ensuring safety of hazardous or dangerous substances |
US7221900B2 (en) * | 2002-11-21 | 2007-05-22 | Kimberly-Clark Worldwide, Inc. | Jamming device against RFID smart tag systems |
US7490054B2 (en) * | 2002-11-21 | 2009-02-10 | Kimberly-Clark Worldwide, Inc. | RFID system and method for vending machine control |
US6982640B2 (en) | 2002-11-21 | 2006-01-03 | Kimberly-Clark Worldwide, Inc. | RFID system and method for tracking food freshness |
US7617132B2 (en) | 2002-11-21 | 2009-11-10 | Kimberly-Clark Worldwide, Inc. | RFID system and method for ensuring food safety |
US6853303B2 (en) * | 2002-11-21 | 2005-02-08 | Kimberly-Clark Worldwide, Inc. | RFID system and method for ensuring personnel safety |
US20040103034A1 (en) * | 2002-11-21 | 2004-05-27 | Kimberly-Clark Worldwide, Inc. | RFID system and method for purchase item accountability |
JP4226880B2 (en) * | 2002-11-29 | 2009-02-18 | 三星電子株式会社 | Ultra wideband wireless transmitter |
US6722260B1 (en) | 2002-12-11 | 2004-04-20 | Rosemount Inc. | Hydraulic piston position sensor |
US6722261B1 (en) | 2002-12-11 | 2004-04-20 | Rosemount Inc. | Hydraulic piston position sensor signal processing |
US20040152988A1 (en) * | 2003-01-31 | 2004-08-05 | Weirich John Paul | Capsule imaging system |
CA2526133C (en) * | 2003-05-22 | 2012-04-10 | General Atomics | Ultra-wideband radar system using sub-band coded pulses |
US20040249257A1 (en) * | 2003-06-04 | 2004-12-09 | Tupin Joe Paul | Article of manufacture for extracting physiological data using ultra-wideband radar and improved signal processing techniques |
DE10341286A1 (en) * | 2003-09-04 | 2005-04-28 | Daimler Chrysler Ag | Access control system for vehicles |
JP4221480B2 (en) * | 2003-09-09 | 2009-02-12 | 独立行政法人情報通信研究機構 | Transmission system and transmission apparatus using ultra-wideband bandpass filter |
JP4519435B2 (en) | 2003-09-25 | 2010-08-04 | 富士通コンポーネント株式会社 | In-vehicle system |
US7839916B1 (en) | 2003-10-08 | 2010-11-23 | L-3 Communications Corporation | Systems and methods for communication in a global positioning system (GPS) device |
KR100786186B1 (en) | 2003-10-17 | 2007-12-21 | 아이신세이끼가부시끼가이샤 | Proximity sensor |
US8120521B2 (en) * | 2003-10-28 | 2012-02-21 | Preco Electronics, Inc. | Radar echolocater with audio output |
US7199749B2 (en) * | 2003-12-12 | 2007-04-03 | Georgia Tech Research Corporation | Radar detection device employing a scanning antenna system |
US7463142B2 (en) | 2003-12-30 | 2008-12-09 | Kimberly-Clark Worldwide, Inc. | RFID system and method for tracking environmental data |
US20050149414A1 (en) * | 2003-12-30 | 2005-07-07 | Kimberly-Clark Worldwide, Inc. | RFID system and method for managing out-of-stock items |
US7853477B2 (en) * | 2003-12-30 | 2010-12-14 | O'shea Michael D | RF-based electronic system and method for automatic cross-marketing promotional offers and check-outs |
US7814582B2 (en) | 2003-12-31 | 2010-10-19 | Kimberly-Clark Worldwide, Inc. | System and method for measuring and monitoring overflow or wetness conditions in a washroom |
US7506547B2 (en) * | 2004-01-26 | 2009-03-24 | Jesmonth Richard E | System and method for generating three-dimensional density-based defect map |
CN100533171C (en) | 2004-02-09 | 2009-08-26 | 安立股份有限公司 | Radar apparatus |
US7148836B2 (en) * | 2004-03-05 | 2006-12-12 | The Regents Of The University Of California | Obstacle penetrating dynamic radar imaging system |
JP2005265461A (en) | 2004-03-16 | 2005-09-29 | Fujitsu Ten Ltd | Radar system |
WO2005088850A1 (en) * | 2004-03-17 | 2005-09-22 | Brother Kogyo Kabushiki Kaisha | Position detection system, response device and query device, radio communication system, position detection method, position detection program, and information recording medium |
JP4620959B2 (en) * | 2004-03-26 | 2011-01-26 | キヤノン株式会社 | Biological information monitor device |
JP4154675B2 (en) * | 2004-03-30 | 2008-09-24 | アイシン精機株式会社 | Condition detection sensor |
US7333047B2 (en) * | 2004-05-28 | 2008-02-19 | Time Domain Corporation | System and method for spatially diverse radar signal processing |
US7432847B2 (en) * | 2004-06-03 | 2008-10-07 | Wireless 2000 Rf & Uwb Technologies Ltd. | Ultra-wideband transceiver |
US7473228B2 (en) * | 2004-07-08 | 2009-01-06 | Delphi Technologies, Inc. | System and method for monitoring a respiration rate of an occupant of a predetermined volume |
RU2007104931A (en) * | 2004-07-09 | 2008-08-20 | Интиллектчуал Проперти Бэнк Корп. (Jp) | METHOD FOR DISPLAYING BIOLOGICAL INFORMATION USING ELECTROMAGNETIC WAVES IN THE BAND OF MILLIMETER WAVES, A DEVICE FOR THE COLLECTION AND DISPLAY OF BIOLOGICAL INFORMATION |
US20060061504A1 (en) * | 2004-09-23 | 2006-03-23 | The Regents Of The University Of California | Through wall detection and tracking system |
US20060066095A1 (en) * | 2004-09-27 | 2006-03-30 | Haack Douglas F | V-fold information presentation device |
RU2258942C1 (en) * | 2004-09-28 | 2005-08-20 | Лайф Сенсор Ко., Лтд. | Method for stabilizing temporal position of ultra-broadband signal and locator for monitoring living objects, realizing said method |
CN1906499B (en) * | 2004-10-14 | 2010-06-02 | 安立股份有限公司 | Small and low power consumption short pulse radar having time lag between transmission and reception arbitrarily variable with high time resolution and its control method |
EP1815267B1 (en) | 2004-11-15 | 2015-06-10 | Nanotron Technologies GmbH | Symmetrical multipath method for determining the distance between two transceivers |
US20060145853A1 (en) * | 2004-12-22 | 2006-07-06 | Time Domain Corporation | System and method for detecting objects and communicating information |
JP4782429B2 (en) * | 2005-01-13 | 2011-09-28 | 富士通株式会社 | UWB radar equipment |
US7423575B2 (en) * | 2005-01-26 | 2008-09-09 | Sentel Corporation | Method and apparatus for protecting personnel and material from RF-based threats using ultra-wideband (UWB) transmission |
US7138936B2 (en) * | 2005-01-26 | 2006-11-21 | Sentel Corporation | Method and apparatus for protecting personnel from RF-triggered explosive devices (RTED) using ultra-wideband (UWB) transmission |
WO2007100311A2 (en) * | 2005-01-26 | 2007-09-07 | Sentel Corporation | Method and apparatus for protecting personnel and materiel from rf-based threats using ultra-widebandi (uwb) transmission |
US7199747B2 (en) * | 2005-05-03 | 2007-04-03 | M/A-Com, Inc. | Generating a fine time offset using a SiGe pulse generator |
US20060001545A1 (en) * | 2005-05-04 | 2006-01-05 | Mr. Brian Wolf | Non-Intrusive Fall Protection Device, System and Method |
WO2008013515A2 (en) * | 2005-05-13 | 2008-01-31 | Thyssen Elevator Capital Corp. | Elevator system including an ultra wideband device |
JP4091061B2 (en) * | 2005-05-19 | 2008-05-28 | 富士通株式会社 | Library device and cartridge for library device |
JP3784823B1 (en) | 2005-07-15 | 2006-06-14 | 国立大学法人徳島大学 | Distance measuring device, distance measuring method, and distance measuring program |
TWI268772B (en) * | 2005-09-02 | 2006-12-21 | Ind Tech Res Inst | Physiological status monitoring system and method |
DE102005054128A1 (en) * | 2005-11-14 | 2007-05-16 | Bosch Gmbh Robert | Machine tool monitoring device |
US8502729B2 (en) | 2006-01-30 | 2013-08-06 | Lawrence Livermore National Security, Llc | Ultra-wideband radar sensors and networks |
US8098707B2 (en) * | 2006-01-31 | 2012-01-17 | Regents Of The University Of Minnesota | Ultra wideband receiver |
US20070196621A1 (en) * | 2006-02-02 | 2007-08-23 | Arnold Frances | Sprayable micropulp composition |
US7643227B2 (en) * | 2006-02-23 | 2010-01-05 | Olympus Corporation | Lens system and optical apparatus |
KR101414586B1 (en) | 2006-03-06 | 2014-07-03 | 센시오텍 아이엔씨 | Ultra wideband monitoring systems and antennas |
US20070210935A1 (en) * | 2006-03-10 | 2007-09-13 | Intellipark, Llc | Electronic parking meter with vehicle detecting sensor |
KR100774362B1 (en) | 2006-04-14 | 2007-11-08 | 주식회사 에스씨티 | Control Process using this Control Installation using RFID and UWB Communication |
JPWO2007122873A1 (en) * | 2006-04-20 | 2009-09-03 | アンリツ株式会社 | Short pulse radar and control method thereof |
US7916066B1 (en) * | 2006-04-27 | 2011-03-29 | Josef Osterweil | Method and apparatus for a body position monitor and fall detector using radar |
US7567200B1 (en) | 2006-04-27 | 2009-07-28 | Josef Osterweil | Method and apparatus for body position monitor and fall detect ion using radar |
RU2311658C9 (en) * | 2006-05-11 | 2008-05-10 | Лайф Сенсор Ко., Лтд. | Sensor for finding moving objects by means of ultra-broadband signal probing (variants) |
EP1860458A1 (en) * | 2006-05-22 | 2007-11-28 | Interuniversitair Microelektronica Centrum | Detection of resonant tags by UWB radar |
CA2654095C (en) * | 2006-06-01 | 2015-12-22 | Biancamed Ltd. | Apparatus, system, and method for monitoring physiological signs |
US20100066587A1 (en) * | 2006-07-14 | 2010-03-18 | Brian Masao Yamauchi | Method and System for Controlling a Remote Vehicle |
US20080029703A1 (en) * | 2006-08-01 | 2008-02-07 | Robert Bosch Gmbh | System and method for range selectable motion detection |
DE102007041098A1 (en) | 2006-09-04 | 2008-03-06 | Robert Bosch Gmbh | Machine tool monitoring device |
DE102007041664A1 (en) * | 2006-09-04 | 2008-04-03 | Robert Bosch Gmbh | Monitoring device for machine tool i.e. stationary circular saw bench, has detection unit for detecting using condition in machine tool based on detection of human or animal tissue, and sensor arranged above or below working surface |
DE102007039571A1 (en) * | 2006-09-04 | 2008-03-06 | Robert Bosch Gmbh | Machine tool monitoring device |
DE102007039570A1 (en) * | 2006-09-04 | 2008-03-06 | Robert Bosch Gmbh | Machine tool monitoring device |
CN104352224B (en) * | 2006-11-01 | 2017-01-11 | 瑞思迈传感器技术有限公司 | System and method for monitoring cardiorespiratory parameters |
US7889753B2 (en) * | 2006-11-16 | 2011-02-15 | Qualcomm Incorporated | Multiple access techniques for a wireless communication medium |
US8014425B2 (en) | 2006-11-16 | 2011-09-06 | Qualcomm Incorporated | Multiple access techniques for a wireless communiation medium |
JP5224723B2 (en) * | 2007-05-18 | 2013-07-03 | 三菱電機特機システム株式会社 | Microwave detection system and microwave detection method |
US8463361B2 (en) | 2007-05-24 | 2013-06-11 | Lifewave, Inc. | System and method for non-invasive instantaneous and continuous measurement of cardiac chamber volume |
US8115673B1 (en) * | 2007-08-11 | 2012-02-14 | Mcewan Technologies, Llc | Self-oscillating UWB emitter-detector |
JP4922098B2 (en) * | 2007-08-17 | 2012-04-25 | 富士通株式会社 | Ultra wideband radar apparatus and signal processing method for wideband radar apparatus |
US7884757B2 (en) * | 2007-10-18 | 2011-02-08 | Tialinx, Inc. | Scanning ultra wideband impulse radar |
EP2051100A1 (en) * | 2007-10-19 | 2009-04-22 | Ford Global Technologies, LLC | A method and system for presence detection |
US20160347213A1 (en) * | 2007-11-11 | 2016-12-01 | Dominic Joseph Pretta | Smart transportation safety module |
CN102047576B (en) * | 2008-05-27 | 2014-07-30 | 松下电器产业株式会社 | Reception device |
US8295769B2 (en) * | 2008-09-15 | 2012-10-23 | Sony Mobile Communications Ab | Wireless connection for data devices |
JP5382765B2 (en) * | 2008-09-19 | 2014-01-08 | 三井造船株式会社 | POSITION INFORMATION DETECTING DEVICE AND POSITION INFORMATION DETECTING METHOD |
EP2350898B1 (en) * | 2008-09-24 | 2020-05-20 | ResMed Sensor Technologies Limited | Contactless and minimal-contact monitoring of quality of life parameters for assessment and intervention |
JP5565823B2 (en) * | 2008-10-07 | 2014-08-06 | 独立行政法人情報通信研究機構 | Pulse signal generator |
US8461989B2 (en) | 2008-10-16 | 2013-06-11 | Lawrence Livermore National Security, Llc. | Smart container UWB sensor system for situational awareness of intrusion alarms |
US8532235B2 (en) * | 2008-12-17 | 2013-09-10 | Lawrence Livermore National Security, Llc. | UWB delay and multiply receiver |
DE102009005110B3 (en) * | 2009-01-19 | 2010-11-18 | Siemens Aktiengesellschaft | Motion detection using the UWB radar system during particle therapy irradiation |
EP2208831A1 (en) * | 2009-01-20 | 2010-07-21 | Geberit International AG | Method and electronic control device for contact-less control of a sanitary assembly |
US9526429B2 (en) * | 2009-02-06 | 2016-12-27 | Resmed Sensor Technologies Limited | Apparatus, system and method for chronic disease monitoring |
EP2698110A1 (en) | 2009-02-27 | 2014-02-19 | Pneumosonics, Inc. | Non-invasive pneumothorax detection method and apparatus |
JP4953325B2 (en) * | 2009-03-12 | 2012-06-13 | キャタピラー エス エー アール エル | Work machine |
US9002427B2 (en) | 2009-03-30 | 2015-04-07 | Lifewave Biomedical, Inc. | Apparatus and method for continuous noninvasive measurement of respiratory function and events |
US20100274145A1 (en) | 2009-04-22 | 2010-10-28 | Tupin Jr Joe Paul | Fetal monitoring device and methods |
EP2756799B1 (en) * | 2009-06-26 | 2016-04-20 | Cianna Medical, Inc. | System for localizing markers or tissue structures within a body |
US9386942B2 (en) | 2009-06-26 | 2016-07-12 | Cianna Medical, Inc. | Apparatus, systems, and methods for localizing markers or tissue structures within a body |
US9032565B2 (en) | 2009-12-16 | 2015-05-19 | Kohler Co. | Touchless faucet assembly and method of operation |
US20110159817A1 (en) * | 2009-12-29 | 2011-06-30 | Pirelli Tyre S.P.A. | Method and system for managing communications between sensor devices included in a tyre and a sensor coordinator device |
US9024814B2 (en) | 2010-01-05 | 2015-05-05 | The Invention Science Fund I, Llc | Tracking identities of persons using micro-impulse radar |
US20110166940A1 (en) * | 2010-01-05 | 2011-07-07 | Searete Llc | Micro-impulse radar detection of a human demographic and delivery of targeted media content |
US20110166937A1 (en) * | 2010-01-05 | 2011-07-07 | Searete Llc | Media output with micro-impulse radar feedback of physiological response |
US9069067B2 (en) | 2010-09-17 | 2015-06-30 | The Invention Science Fund I, Llc | Control of an electronic apparatus using micro-impulse radar |
US8884813B2 (en) * | 2010-01-05 | 2014-11-11 | The Invention Science Fund I, Llc | Surveillance of stress conditions of persons using micro-impulse radar |
US9019149B2 (en) | 2010-01-05 | 2015-04-28 | The Invention Science Fund I, Llc | Method and apparatus for measuring the motion of a person |
KR101079391B1 (en) | 2010-02-18 | 2011-11-02 | 김지현 | System and Method for Preventing Collision Using Through-Wall Measurements of Radar |
US8717430B2 (en) | 2010-04-26 | 2014-05-06 | Medtronic Navigation, Inc. | System and method for radio-frequency imaging, registration, and localization |
JP5284310B2 (en) * | 2010-05-17 | 2013-09-11 | 富士通株式会社 | Broadband radar apparatus and control method for broadband radar apparatus |
JP5630122B2 (en) * | 2010-07-28 | 2014-11-26 | 富士通株式会社 | Imaging apparatus and transmission / reception apparatus |
US8844361B2 (en) * | 2010-07-30 | 2014-09-30 | The Watt Stopper, Inc. | Ultrasonic sensor control system for occupancy sensing |
CN101968541B (en) * | 2010-09-17 | 2012-07-11 | 国营红林机械厂 | Pulse ultra-wideband ranging system |
US9442189B2 (en) * | 2010-10-27 | 2016-09-13 | The Fourth Military Medical University | Multichannel UWB-based radar life detector and positioning method thereof |
US8779966B2 (en) * | 2010-11-16 | 2014-07-15 | Tialinx, Inc. | Remote interrogation for detection of activity or living organisms inside electronically conductive containers |
RU2469350C2 (en) * | 2010-12-27 | 2012-12-10 | Государственное образовательное учреждение высшего профессионального образования "Волгоградский государственный университет" | Radar monitoring device |
US20120170618A1 (en) * | 2011-01-04 | 2012-07-05 | ABG Tag & Traq, LLC | Ultra wideband time-delayed correlator |
EP3312629A3 (en) | 2011-02-21 | 2018-06-13 | Transrobotics, Inc. | System and method for sensing an object's dimensions |
EP2517621A1 (en) | 2011-04-29 | 2012-10-31 | Nederlandse Organisatie voor toegepast -natuurwetenschappelijk onderzoek TNO | A radar apparatus for detecting multiple life-signs of a subject, a method and a computer program product |
US9000973B2 (en) * | 2011-04-29 | 2015-04-07 | The Invention Science Fund I, Llc | Personal electronic device with a micro-impulse radar |
US9103899B2 (en) | 2011-04-29 | 2015-08-11 | The Invention Science Fund I, Llc | Adaptive control of a personal electronic device responsive to a micro-impulse radar |
US9151834B2 (en) | 2011-04-29 | 2015-10-06 | The Invention Science Fund I, Llc | Network and personal electronic devices operatively coupled to micro-impulse radars |
US8884809B2 (en) * | 2011-04-29 | 2014-11-11 | The Invention Science Fund I, Llc | Personal electronic device providing enhanced user environmental awareness |
CN105891786B (en) | 2011-10-19 | 2019-07-26 | B·苏博拉曼亚 | Directed velocity and range sensor |
US8264401B1 (en) | 2011-12-29 | 2012-09-11 | Sensys Networks, Inc. | Micro-radar, micro-radar sensor nodes, networks and systems |
US9713434B2 (en) * | 2012-02-11 | 2017-07-25 | Sensifree Ltd. | Microwave contactless heart rate sensor |
US9473865B2 (en) | 2012-03-01 | 2016-10-18 | Conexant Systems, Inc. | Integrated motion detection using changes in acoustic echo path |
EP2695297B1 (en) * | 2012-05-02 | 2015-07-08 | Institute of Electronics and Computer Science | Ultra-wideband sharpener for excitation a symmetric antenna |
US9445729B2 (en) * | 2012-07-20 | 2016-09-20 | Resmed Sensor Technologies Limited | Range gated radio frequency physiology sensor |
RU2501032C1 (en) * | 2012-08-03 | 2013-12-10 | Федеральное государственное унитарное предприятие "Центральный научно-исследовательский институт химии и механики" (ФГУП "ЦНИИХМ") | Method of determining permeability of barrier for broadband radar probing radiation |
WO2014055755A1 (en) | 2012-10-05 | 2014-04-10 | TransRobotics, Inc. | Systems and methods for high resolution distance sensing and applications |
TWI464407B (en) * | 2012-11-30 | 2014-12-11 | Ind Tech Res Inst | Electronic device and method for sensing active state of object |
US9877659B2 (en) | 2012-11-30 | 2018-01-30 | Industrial Technology Research Institute | Sensing system and method for physiology measurements |
US11004337B2 (en) | 2012-12-28 | 2021-05-11 | Balu Subramanya | Advanced parking management system |
US9713437B2 (en) | 2013-01-26 | 2017-07-25 | Cianna Medical, Inc. | Microwave antenna apparatus, systems, and methods for localizing markers or tissue structures within a body |
US10660542B2 (en) | 2013-01-26 | 2020-05-26 | Cianna Medical, Inc. | RFID markers and systems and methods for identifying and locating them |
JP6127602B2 (en) * | 2013-03-13 | 2017-05-17 | 沖電気工業株式会社 | State recognition device, state recognition method, and computer program |
CN103308898B (en) * | 2013-05-20 | 2016-07-13 | 中电科仪器仪表有限公司 | A kind of list station pulse RCS based on switch switching tests system |
US9532735B2 (en) * | 2013-10-23 | 2017-01-03 | King Abdullah University Of Science And Technology | Apparatus and method for wireless monitoring using ultra-wideband frequencies |
US9761049B2 (en) | 2014-03-28 | 2017-09-12 | Intel Corporation | Determination of mobile display position and orientation using micropower impulse radar |
EA031233B1 (en) | 2014-04-24 | 2018-12-28 | Эни С.П.А. | Method and system for the remote monitoring of the two- or three-dimensional field of displacements and vibrations of objects and structures |
EA031205B1 (en) | 2014-04-24 | 2018-11-30 | Эни С.П.А. | Kinematic calibration system and method for measuring displacements and vibrations of objects and structures |
US10018716B2 (en) * | 2014-06-26 | 2018-07-10 | Honeywell International Inc. | Systems and methods for calibration and optimization of frequency modulated continuous wave radar altimeters using adjustable self-interference cancellation |
JP6271384B2 (en) * | 2014-09-19 | 2018-01-31 | 株式会社東芝 | Inspection device |
RU2580828C1 (en) * | 2014-12-29 | 2016-04-10 | Федеральное государственное бюджетное образовательное учреждение высшего профессионального образования "Московский государственный технический университет имени Н.Э. Баумана (МГТУ им. Н.Э. Баумана) | Radar device for measuring location of after-penetration object |
US10130301B2 (en) | 2015-01-22 | 2018-11-20 | Elwha Llc | Devices and methods for remote hydration measurement |
US10159439B2 (en) | 2015-01-22 | 2018-12-25 | Elwha Llc | Devices and methods for remote hydration measurement |
US9958540B2 (en) | 2015-02-24 | 2018-05-01 | S-1 Corporation | Ultra-wideband transceiver, signal transmission and reception method thereof, and ultra-wideband radar sensor including the same |
JP6429689B2 (en) * | 2015-03-16 | 2018-11-28 | 三菱電機株式会社 | Sensor control system |
US9925122B2 (en) | 2015-03-30 | 2018-03-27 | Elwha Llc | Systems and methods for controlling delivery of breast milk supplementation |
US10016341B2 (en) | 2015-03-30 | 2018-07-10 | Elwha Llc | Systems and devices for controlling delivery of breast milk supplementation |
US9968523B2 (en) | 2015-03-30 | 2018-05-15 | Elwha Llc | Systems and devices for controlling delivery of breast milk supplementation |
US10290372B2 (en) | 2015-03-30 | 2019-05-14 | Elwha Llc | Systems and devices for controlling delivery of breast milk supplementation |
EP3842822A3 (en) | 2015-04-20 | 2021-09-08 | ResMed Sensor Technologies Limited | Multi sensor radio frequency detection |
EP3286579B1 (en) | 2015-04-20 | 2021-06-02 | ResMed Sensor Technologies Limited | Gesture recognition with sensors |
WO2016170005A1 (en) | 2015-04-20 | 2016-10-27 | Resmed Sensor Technologies Limited | Detection and identification of a human from characteristic signals |
US10610326B2 (en) | 2015-06-05 | 2020-04-07 | Cianna Medical, Inc. | Passive tags, and systems and methods for using them |
WO2017029284A1 (en) | 2015-08-14 | 2017-02-23 | Resmed Sensor Technologies Limited | Digital range gated radio frequency sensor |
CN105342616B (en) * | 2015-09-23 | 2018-03-20 | 宁波小匠物联网科技有限公司 | The detecting system and its detection method of human body sitting state |
RU2610146C1 (en) * | 2015-09-29 | 2017-02-08 | Федеральное государственное казённое образовательное учреждение высшего профессионального образования "Калининградский пограничный институт Федеральной службы безопасности Российской Федерации" | Radio-wave doppler detector |
WO2017123299A1 (en) * | 2015-10-14 | 2017-07-20 | Anritsu Company | Frequency-scalable imaging radar |
US10964426B2 (en) * | 2015-10-16 | 2021-03-30 | General Electric Company | Methods and systems to sense situational awareness with a dual doppler and control for optimized operations |
US20180353138A1 (en) | 2015-12-08 | 2018-12-13 | Resmed Limited | Non-contact diagnosis and monitoring of sleep disorders |
US9817439B2 (en) | 2016-02-29 | 2017-11-14 | JumpStartCSR, Inc. | System, method and device for designing, manufacturing, and monitoring custom human-interfacing devices |
CA3016334A1 (en) | 2016-03-03 | 2017-09-08 | Cianna Medical, Inc. | Implantable markers, and systems and methods for using them |
WO2017177074A1 (en) | 2016-04-06 | 2017-10-12 | Cianna Medical, Inc. | Reflector markers and systems and methods for identifying and locating them |
WO2018033574A1 (en) | 2016-08-16 | 2018-02-22 | Resmed Sensor Technologies Limited | Digital radio frequency motion detection sensor |
AU2017313146B2 (en) * | 2016-08-18 | 2021-09-16 | Robert Bosch Gmbh | High security motion sensor |
US10495728B2 (en) * | 2017-03-06 | 2019-12-03 | Honeywell International Inc. | Signal interference prevention system for a frequency-modulated continuous wave radar altimeter |
WO2018175667A1 (en) | 2017-03-21 | 2018-09-27 | Cianna Medical, Inc. | Reflector markers and systems and methods for identifying and locating them |
US10062254B1 (en) * | 2017-04-03 | 2018-08-28 | Alexander Paul | Intrusion detection system |
RU2656532C1 (en) * | 2017-06-07 | 2018-06-05 | Федеральное государственное бюджетное образовательное учреждение высшего образования "Саратовский национальный исследовательский государственный университет имени Н.Г. Чернышевского" | Method of remote control of movement of the surface of an object |
CN107070464B (en) * | 2017-06-13 | 2023-03-28 | 吉林大学 | Multi-path synchronous frequency division multiplexing millimeter wave frequency sweep signal generation device and method |
US11067678B2 (en) | 2017-07-20 | 2021-07-20 | Electronics And Telecommunications Research Institute | Radar device using delay |
JP6588525B2 (en) * | 2017-12-18 | 2019-10-09 | 株式会社日本ジー・アイ・ティー | Parking lot management system |
US11883150B2 (en) | 2018-09-06 | 2024-01-30 | Cianna Medical, Inc. | Systems for identifying and locating reflectors using orthogonal sequences of reflector switching |
CN109100698B (en) * | 2018-09-17 | 2019-08-30 | 中国电子科技集团公司第二十八研究所 | A kind of radar target spherical projection method for maritime formation |
CN111134685B (en) * | 2018-11-02 | 2022-08-09 | 富士通株式会社 | Fall detection method and device |
CN109725305A (en) * | 2019-01-02 | 2019-05-07 | 公安部第一研究所 | A kind of ultra wideband radar system of Low Power High Performance |
US11703593B2 (en) | 2019-04-04 | 2023-07-18 | TransRobotics, Inc. | Technologies for acting based on object tracking |
RU2730988C1 (en) * | 2019-09-10 | 2020-08-26 | Саркис Манукович Казарян | Method for measuring heart rate and respiratory rate and radar heart rate and respiratory rate meter |
DE102020126534A1 (en) * | 2020-10-09 | 2022-04-14 | Eto Magnetic Gmbh | Sensor device and method for monitoring a coupling state of a coupling element |
CN116964649A (en) | 2020-12-16 | 2023-10-27 | 新鲜混合物有限公司 | Intelligent inventory management system for a dispensing and in-cup mixing beverage platform |
RU2755202C1 (en) * | 2020-12-25 | 2021-09-14 | Акционерное общество "Всероссийский научно-исследовательский институт "Сигнал" | Autodyne-based pulse location device |
DE102021110138A1 (en) | 2021-04-21 | 2022-10-27 | Bayerische Motoren Werke Aktiengesellschaft | Vehicle, computer program, method and transceiver circuitry for a vehicle |
DE102022116737A1 (en) | 2022-07-05 | 2024-01-11 | Friedrich-Alexander-Universität Erlangen-Nürnberg, Körperschaft des öffentlichen Rechts | System, method, computer program and computer-readable medium |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3686669A (en) * | 1970-04-24 | 1972-08-22 | William J Toulis | Detection and classification system utilizing unipolar pulses |
US3772697A (en) * | 1971-04-19 | 1973-11-13 | Sperry Rand Corp | Base-band pulse object sensor system |
US3750169A (en) * | 1972-03-13 | 1973-07-31 | Sperry Rand Corp | Vehicular safety system |
US4150375A (en) * | 1978-03-02 | 1979-04-17 | Sperry Rand Corporation | Interferometric protective system for vehicles |
US4907001A (en) * | 1987-08-21 | 1990-03-06 | Geophysical Survey Systems, Inc. | Extraction of radar targets from clutter |
US5049887A (en) * | 1990-10-16 | 1991-09-17 | Sperry Marine Inc. | Target range detector with moving target indication |
US5148174A (en) * | 1991-02-13 | 1992-09-15 | Geophysical Survey Systems, Inc. | Selective reception of carrier-free radar signals with large relative bandwidth |
-
1993
- 1993-04-12 US US08044717 patent/US5361070B1/en not_active Expired - Lifetime
-
1994
- 1994-04-08 EP EP94928687A patent/EP0694171B1/en not_active Revoked
- 1994-04-08 CA CA002160352A patent/CA2160352C/en not_active Expired - Lifetime
- 1994-04-08 DE DE69430195T patent/DE69430195T2/en not_active Revoked
- 1994-04-08 JP JP52333894A patent/JP3471803B2/en not_active Expired - Lifetime
- 1994-04-08 WO PCT/US1994/003892 patent/WO1994024579A1/en active IP Right Grant
- 1994-04-08 KR KR1019950704500A patent/KR100322662B1/en not_active IP Right Cessation
- 1994-04-08 AT AT94928687T patent/ATE214853T1/en not_active IP Right Cessation
- 1994-04-08 DE DE69434064T patent/DE69434064T2/en not_active Revoked
- 1994-04-08 EP EP01119373A patent/EP1178330B1/en not_active Revoked
- 1994-04-08 AT AT01119373T patent/ATE278969T1/en not_active IP Right Cessation
- 1994-04-08 CA CA 2503382 patent/CA2503382C/en not_active Expired - Lifetime
-
2003
- 2003-06-17 JP JP2003172294A patent/JP3648236B2/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
DE69430195T2 (en) | 2002-10-24 |
WO1994024579A1 (en) | 1994-10-27 |
DE69434064D1 (en) | 2004-11-11 |
EP0694171B1 (en) | 2002-03-20 |
JP3471803B2 (en) | 2003-12-02 |
EP1178330B1 (en) | 2004-10-06 |
DE69430195D1 (en) | 2002-04-25 |
CA2503382C (en) | 2008-08-05 |
KR100322662B1 (en) | 2002-06-20 |
JP2004004100A (en) | 2004-01-08 |
JP3648236B2 (en) | 2005-05-18 |
EP1178330A1 (en) | 2002-02-06 |
ATE278969T1 (en) | 2004-10-15 |
CA2503382A1 (en) | 1994-10-27 |
KR960702111A (en) | 1996-03-28 |
US5361070A (en) | 1994-11-01 |
ATE214853T1 (en) | 2002-04-15 |
EP0694171A4 (en) | 1996-04-17 |
CA2160352A1 (en) | 1994-10-27 |
DE69434064T2 (en) | 2005-10-06 |
US5361070B1 (en) | 2000-05-16 |
EP0694171A1 (en) | 1996-01-31 |
JPH08511341A (en) | 1996-11-26 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CA2160352C (en) | Ultra-wideband radar motion sensor | |
EP0901642B1 (en) | Pulse homodyne field disturbance sensor | |
CA2199121C (en) | Range-gated field disturbance sensor with range-sensitivity compensation | |
US5576627A (en) | Narrow field electromagnetic sensor system and method | |
US6518915B2 (en) | Impulse radar security system | |
US6456231B1 (en) | Radar sensor having a CFAR detector | |
JP3604396B2 (en) | Distance gate strip proximity sensor | |
US4686534A (en) | Retro directive radar and target simulator beacon apparatus and method | |
US20080111686A1 (en) | System and Method for Detecting an Intruder Using Impulse Radio Technology | |
US20020158790A1 (en) | System and method for intrusion detection using a time domain radar array | |
US20020175850A1 (en) | Method of envelope detection and image generation | |
Fontana et al. | An ultra wideband radar for micro air vehicle applications | |
US4072944A (en) | Imminent collision detection apparatus | |
CA2605339C (en) | Ultra-wideband radar motion sensor | |
US5220328A (en) | Target motion detecting impulse doppler radar system | |
Barnes | Covert range gated wall penetrating motion sensor provides benefits for surveillance and forced entries | |
Perkins et al. | A Low Cost, Accurate, Target Detecting Device for Altimetry and Fuzing |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
EEER | Examination request | ||
MKEX | Expiry |
Effective date: 20140408 |
|
MKEX | Expiry |
Effective date: 20140408 |