Abstract: A Pulse-Doppler radar apparatus is constructed such that an output of an oscillator is divided by a distributor and an on/off switch for generating pulses is coupled to an IF input of a first harmonic mixer, in order to improve precision in measurement of a distance and speed.

Abstract: A method and apparatus of detecting termites in which microwaves are transmitted into a region and reflected microwaves are detected. The received signals are processed to identify the presence or otherwise of termites or other insects. Various hardware configurations and signal processing algorithms are described including planar antenna arrays and neural net signal processing. The system comprises a microwave assembly, modulator and a processor. Microwaves are transmitted into a structure and the reflected microwaves are received in the microwave assembly. The output of the processor is displayed on a display.

Abstract: A system and method for highly selective intrusion detection using a sparse array of time modulated ultra wideband (TM-UWB) radars. Two or more TM-UWB radars are arranged in a sparse array around the perimeter of a building. Each TM-UWB radar transmits ultra wideband pulses that illuminate the building and the surrounding area. Signal return data is processed to determine, among other things, whether an alarm condition has been triggered. High resolution radar images are formed that give an accurate picture of the inside of the building and the surrounding area. This image is used to detect motion in a highly selective manner and to track moving objects within the building and the surrounding area. Motion can be distinguished based on criteria appropriate to the environment in which the intrusion detection system operates.

Abstract: A signal processing method is particularly for use in object detection systems which allows a sensed target signal to be “held” once it has raised above a detection-threshold. The method involves reducing the detection-threshold values of the detection-threshold function within the target region. This method is useful for such applications as automotive radar sensors, airbag deployment systems, communication systems demodulation, security sensor systems, sanitary flushing systems and lighting systems.

Abstract: An electronic counter-measure receiver can be colocated with a threat simulator radar, which transmits a radar signal. As a pulsed-Doppler signal, this transmitted radar signal is sampled as a reference signal by the receiver to determine quadrature, coherent matched filter coefficients. A return signal is received and processed with the reference signal as quadrature signal components with the quadrature, coherent matched filter coefficients within a matched filter. The return signal is processed as a first intermediate frequency via a mixer and local oscillator and a second quadrature intermediate frequency via a digital local oscillator and mixer. A fast Fourier transform is performed to determine Doppler information. In a continuous wave transmission for sampling arbitrary but unevenly spaced in time pulses are generated from a pulse generator source internal to the receiver.

Abstract: A fluid flow device includes an actuator, an RF transmitter, a gated RF receiver, and a processor. The RF transmitter is configured and arranged to produce a plurality of pulses of RF energy spaced apart in time to form a sensor field. The gated RF receiver is configured and arranged to receive RF energy reflected by objects within the sensor field. The processor is coupled to the gated RF receiver for evaluating the reflected RF energy. The processor is also coupled to the actuator and is configured and arranged to activate the actuator in response to the reflected RF energy to control fluid flow. In addition, a new low power radar sensor operates by providing radar pulses that are non-uniformly spaced in time. In operation, a burst of pulses is initiated in the transmitter. Between each burst is a period of rest time in which the transmitter is not transmitting RF energy.

Abstract: A motion detector combines an FCC approved homodyne pulsed range-gated radar (“RGR”) detector (10) and a PIR detector (158). Narrow microwave pulses are transmitted at a predetermined pulse repetition frequency (“PRF”) and the pulses are reflected by a target. The RGR detector senses the presence of moving human sized objects within predetermined ranges. Moving objects beyond the ranges are not sensed. The RGR detector employs a pulsed microwave oscillator (12) that is triggered by a system clock (14) and immediately retriggered after a 3 to 100 nanosecond delay (20). The duration of each pulse is 3 to 20 nanoseconds with a half-sine envelope shape. The RGR employs a homodyne detector (36) and shares an antenna (38) with the transmitter. The receiver range is determined by the delay imposed between the transmitted pulses, the first being a transmitted pulse and the second being a local oscillator pulse. Each received 5.8 GHz pulse is mixed down to a baseband by the homodyne detector.

Abstract: The invention relates to a receiver system for the reception of a series of ultrashort, pulsed electromagnetic signals. Signals of this type usually require an extremely fast-acting receiver, necessarily situated in close proximity to the antenna. According to the invention, the presence of several passive components near the antenna will suffice.

Abstract: A system and method for high resolution radar imaging using a sparse array of time modulated ultra wideband (TM-UWB) radars. Two or more TM-UWB radars are arranged in a sparse array. Each TM-UWB radar transmits ultra wideband pulses that illuminate a target, and at least one receives the signal returns. The signal return data is processed according to the function being performed, such as imaging or motion detection. The TM-UWB radar array operates in several modes. In a first mode, each TM-UWB radar transmits and receives back scattering returns, and at least one TM-UWB radar receives forward scattering returns. In a second mode, each TM-UWB radar transmits but only one of the radars receives signal returns, both back and forward scattering. In a third mode, each TM-UWB radar transmits and receives back scattering signal returns, but neither receives forward scattering returns.

Abstract: A radar system adapted to be installed on a vehicle (1) is operable to detect objects in different fields of view of the system. The system has transceiver means (2, 3; 44, 46) for transmitting a radar signal and receiving the signal after the latter has been reflected from an object to be detected. A reflected signal is sampled by sampling means (12; 66) during a succession of sampling periods each of which is delayed with respect to a corresponding portion of the transmitted signal. The gating of the reflected signal effectively generates range shells, each of which corresponds to the time taken for a transmitted signal to reach an object at the shell, and to be reflected back to the system and is hence related to the delay between the transmission of the signal and the corresponding sampling period. The range shells define the field of view of the system, which can be changed by altering said delay.

Abstract: A fluid flow device includes an actuator, an RF transmitter, a gated RF receiver, and a processor. The RF transmitter is configured and arranged to produce a plurality of pulses of RF energy spaced apart in time to form a sensor field. The gated RF receiver is configured and arranged to receive RF energy reflected by objects within the sensor field. The processor is coupled to the gated RF receiver for evaluating the reflected RF energy. The processor is also coupled to the actuator and is configured and arranged to activate the actuator in response to the reflected RF energy to control fluid flow. In addition, a new low power radar sensor operates by providing radar pulses that are non-uniformly spaced in time. In operation, a burst of pulses is initiated in the transmitter. Between each burst is a period of rest time in which the transmitter is not transmitting RF energy.

Abstract: An Ultra Wideband (UWB) short-range radar system is used for the detection of targets in clutter. Examples of targets on the ground include human walkers, crawlers and runners, and vehicles. The UWB sensor can also be used to detect small approaching boats in different levels of sea clutter or airborne targets like hang gliders. One of the primary differences between this device and other UWB radar sensors is the manner in which the bias on the threshold detector is set as well as the logic circuitry used to find targets in clutter while maintaining a low false alarm rate. The processing is designed to detect targets in varying degrees of clutter automatically. There may be no front panel controls other than an ON-OFF switch. The system is lightweight, low-cost, and can be easily installed in minutes.

Abstract: Harmonic techniques are employed to leverage low-cost, ordinary surface mount technology (SMT) to high microwave frequencies where tight beamforming with a small antenna makes reliable, high-accuracy pulse-echo radar systems possible. The implementation comprises a 24 GHz short-pulse transceiver comprised of a pulsed harmonic oscillator employed as a transmitter and an integrating, pulsed harmonic sampler employed as a receiver. The transmit oscillator generates a very short (0.5 ns) phase-coherent harmonic-rich oscillation at a sub-multiple of the actual transmitter frequency. A receiver local oscillator operates at a sub-multiple of the transmit frequency and is triggered with controlled timing to provide a very short (0.5 ns), phase-coherent local oscillator burst. The local oscillator burst is coupled to an integrating harmonic sampler to produce an integrated, equivalent-time replica of the received RF.

Abstract: A system and method for highly selective intrusion detection using a sparse array of time modulated ultra wideband (TM-UWB) radars. Two or more TM-UWB radars are arranged in a sparse array around the perimeter of a building. Each TM-UWB radar transmits ultra wideband pulses that illuminate the building and the surrounding area. Signal return data is processed to determine, among other things, whether an alarm condition has been triggered. High resolution radar images are formed that give an accurate picture of the inside of the building and the surrounding area. This image is used to detect motion in a highly selective manner and to track moving objects within the building and the surrounding area. Motion can be distinguished based on criteria appropriate to the environment in which the intrusion detection system operates.

Abstract: An object detecting apparatus uses a radar system 24 which employes a directional antenna 6. A transmission parameter of the system 24 is calibrated for each transmission direction such that, at a boundary 22 of a detection area 20, there is a maximum signal intensity and a minimum sensitivity. The calibration is effected using reflectors of known reflective response which are positioned around the boundary 22 during calibration.

Abstract: The device comprises a transmitter (7) transmitting ultrasound into a predetermined space (5), a sensor (8) which senses the echoes from the transmission by the transmitter into the space in order to deliver a signal representative of the echoes, and electronic device for processing the signal in order to diagnose the possible presence of a moving body in the space (5). It further comprises a) device (10) for scanning the space (5) with the ultrasound beam output by the transmitter (7) and (b) device (11) for simultaneously moving the echo sensor (8) so as to optimize the signal/noise ratio of the output of the sensor (8).

Abstract: A method and apparatus for detecting the presence of objects in a vehicle operator's blind spots. The apparatus comprises a side-facing Doppler radar system using continuous wave (CW) transmission with frequency modulation (FM) operation from a frequency modulation switching technique. The radar system determines the presence, range and closing rate of detected targets. The radar system detects targets even when operated in adverse weather conditions and will not generate false warnings due to rain clutter caused by wet roads and other wet surroundings. The radar system uses ranging techniques to reject false targets that are detected outside of a predetermined target detection zone. In accordance with the present invention, the radar system indicates that a target is detected if and only if any part of the target is within the detection zone and it: (1) remains in front of the antenna for at least TH1 seconds; (2) is at a range between Range.sub.min and Range.sub.

Abstract: A system that provides information to authorized users regarding the location of speed traps via a wireless communication network connected to a computer wide area network. The system includes the use of a detector for speed detecting equipment, such as a radar detector, which detects the presence of speed detecting equipment and transmits the detection information into an electronic device in the motor vehicle. The electronic device communicates is coupled to a physical location device, such as a GPS receiver, which provides the specific location and direction of the motor vehicle when detection occurs. The electronic device is also coupled to a wireless modem that connects to a wireless communication network and to the wide area network. Connected to the wide area network is a central server that receives uploaded information from a plurality of other motor vehicle operators to create a large information database.

Abstract: An electronic device including a wave transmitter covering a determined spatial sensing field, and a wave receiver for controlling an automatic device; a radiating antenna including a waveguide having lateral faces and slots arranged on one of the lateral faces, wherein the slots radiate in planes substantially perpendicular to a longitudinal direction of the waveguide, and wherein the wave transmitter and the wave receiver are arranged at one end of the waveguide; a matched load arranged at an opposite end of the wave guide; substantially identical reflectors arranged over substantially the whole length of the waveguide, wherein the reflectors extend essentially symmetrically with respect to longitudinal plane of symmetry of the waveguide and making a predetermined angle with one another, and wherein the waveguide and the reflectors are composed of at least one piece.

Abstract: A microwave sensor for determining the velocity and direction of a moving object comprises a mixer, phase shifter, and receive/transmit antenna mounted in series, the mixer having a single intermediate frequency output. The intermediate frequency output is switched synchronously with the phase shifter which is switched between 0.degree. phase shift and 45.degree. phase shift. Although the mixer has only a single intermediate frequency output, the switching provides two output channel signals and with a phase difference of 90.degree. therebetween to enable determination of the direction of movement. The single intermediate frequency channel provides intrinsic gain matching of the output channels which eliminates the need for tuning in order to balance output channels as required in conventional sensor.

Abstract: An automatic lamp control device in which a Doppler radar module, a switching unit for switching a lamp circuit on and off, a circuit configuration for evaluating Doppler radar module signals and for producing signals for controlling the switching unit, and a power supply unit for supplying current to the Doppler radar module and to the circuit configuration are provided on a printed circuit board configuration. The lamp control device reacts to movements within the transmitting and receiving range of the Doppler radar module. The range is independent of the ambient temperature. The lamp control device can be configured to save space, in such a way that it can be integrated completely in a standard flush-mounted box.

Abstract: A method for monitoring large surface areas. A thermal camera and an electromagnetic radar are rotated about a vertical axis to scan the area. The area is divided into sector-like surface elements. Monitoring criteria are established for each of the surface elements. Movements in the surface area being monitored are detected by the radar. The thermal camera is used to detect objects different, in temperature, from their surroundings. Detected objects are located in a surface element and identified in accordance with the monitoring criteria using at least one of the radar and thermal camera.

Abstract: This invention discloses a microwave transceiver suitable for use in an intrusion detection system including a microwave radiation generator, a printed antenna on a first side of a printed circuit board for radiating the microwave radiation generated by the microwave generator, and a ground plane on a second side of the printed circuit board and having an outer edge which is generally coextensive with an outer edge of the printed antenna.

Abstract: An electromagnetic method for detecting and/or locating a person constituting a non-cooperative target, in which an electromagnetic signal is transmitted (1) in the vicinity of a search zone (N), and the signal returned by said zone (N) is detected (2) in the vicinity thereof, the method being characterized in that transmission and reception are performed by means of at least two distinct antennas, each signal obtained in this way is filtered by a lowpass or a bandpass filter (12) so as to extract therefrom components corresponding to human movement, and in that each filtered signal obtained in this way is processed (14) to deduce therefrom the presence of a person and/or to locate that person. The system enables the method to be implemented. Application to locating avalanche victims.

Abstract: A pulsed RF oscillator employing a BIAS-ON path and a QUENCH path to produce fast turn-on and fast turn-off RF bursts with well-controlled burst width. The oscillator further includes amplitude and stability control elements, and a 5.8 GHz microstrip implementation is disclosed. The pulsed RF oscillator can be configured with quadrature RF homodyne detectors to form a range-gated pulse-Doppler motion sensor system for sensing target motion within a gated region. The sensor includes a transmitter for transmitting a sequence of RF bursts comprised of a number of cycles at the transmitter frequency. The sensor further includes a receiver responsive to the transmitted bursts and burst echoes from moving targets within its sensing field. The receiver produces Doppler signal with an amplitude representative sum of the transmitted burst and the echo burst. A Doppler motion response occurs for moving targets within a region sharply defined by the transmitted burst width.

Abstract: A pulse Doppler radar motion sensor system and method for sensing target motion within a gated region is provided with approximately constant response versus target distance. The sensor includes a transmitter for transmitting a sequence of RF bursts comprised of a number of cycles at the transmitter frequency. The transmitted burst width alternates at a pattern frequency to provide a pattern of varying burst widths. The sensor includes a receiver responsive to the transmitted bursts and burst echoes from moving targets within its sensing field. The receiver produces a pattern frequency with a signal amplitude representative of the difference in moving target response for two different range gated regions defined by the transmitted burst widths. This difference is detected to provide a range invariant target motion response in a sharply defined region. Another mode provides a quadrature receive channel for target direction determination.

Abstract: A method for determining malfunction of a microwave intrusion detector which transmits microwave radiation into a region and receives microwave radiation to produce a receiver signal, such that a detection pattern of microwave pulses is transmitted periodically during an intrusion detection mode, including initiating a self-test mode of the detector, transmitting during the self-test mode a test pattern comprising a plurality of microwave pulses having at least two different duty cycles, different from the detection pattern, receiving microwave radiation in the self-test mode and generating a receiver signal responsive thereto and analyzing the receiver signal to derive a parameter responsive to the test pattern, so as to determine a malfunction condition.

Abstract: A combined type intrusion and attack sensing device was a microwave oscillation and Doppler detect circuit an intrusion band-pass filter, an attack band-pass filter, two comparators, two alarm driving circuits, and a suspended object. The combined type intrusion and attack sensing device adopts the Doppler effect to sense an intrusion and employs a microwave antenna to transmit a signal in the microwave band within a predetermined range. The signal will be reflected by any object within above range or suspended object vibration, and the reflected wave will be received by the antenna. The reflected wave will be mixed with original signal to generate a difference-frequency signal. The difference-frequency signal is amplified by an intrusion band-pass filter or an attack band-pass filter. The amplified and filtered signal is sent to two comparator circuits for comparison with a reference signal to generate two driving signals to drive one of the two alarm-generating circuits.

Abstract: A microwave motion sensor for detecting multiple levels of motion of a target is disclosed. The motion sensor includes a transceiver for broadcasting a signal into a predetermined area and receiving a reflected signal with a receiver for producing first and second directional signals. A signal conditioning circuit is provided for amplifying the first and second directional signals and digitizing the directional signals. The signal conditioning circuit includes a micro motion amplifier for separately amplifying one of the directional signals and producing a micro motion signal. A processor is provided for receiving the first and second directional signals transmitted by the signal conditioning circuit, and for receiving the micro motion signal. The processor includes a circuit for analyzing the directional signals, and a circuit for comparing the micro motion signal to a threshold.

Abstract: A detection and classification system for underwater objects uses a transting unit and a receiving unit. The transmitting unit comprises a waveform generator, a power amplifier, and a transmitting antenna. The receiving unit comprises a receiving antenna, a pre-amplifier, a first harmonic suppressor, a digitizer, and a computer. The transmitting unit radiates an analog electromagnetic wave signal into a conductive medium such as seawater which the receiving unit detects and analyzes by a differential spectral analysis after conversion of the signal into binary code.The system uses a signal-processing method which includes the steps of determining the size of the underwater object to be detected, transmitting an electromagnetic wave with a wavelength proportioned to the size of the object, performing a spectral analysis of the received signal, performing a spectral analysis at a different time or different location, comparing the two spectra performed, and analyzing the difference between the two spectra.

Abstract: The watching apparatus is provided with a radar probe, and is made such as to detect the presence of human beings. The radar probe includes a command unit and a branching element, inserted between an oscillator circuit and a transmitter stage, as well as a superposing circuit (5), in which a signal, derived from the radar transmitter, is superposed with an echo signal received by a receiver stage. The radar probe is made such as to work as an interference radar, and a delay circuit is inserted into the transmitter-receiver path between the branching element and the superposing circuit in order to increase the travelling time of the radar signal with respect to the branched off signal.

Abstract: In the case of this radar sensor, a phase shifter is inserted between a microwave generator and an antenna and can be switched over between two phases. A demodulator (DM) demodulates the received reflected signal, which has superimposed on it the microwave signal which originates from the microwave generator. A de-multiplexer (DEMUX) which is connected downstream of the demodulator (DM) separates the two phase-shifted demodulated signals. The measurement result is largely noise-free.

Abstract: An apparatus detects living bodies, in particular human living bodies, by ectromagnetic signals. The apparatus has a receiver device for electromagnetic signals that includes a device for obtaining frequency components that are characteristic in respect to living bodies, out of the magnetic signals. The receiver device includes a direct demodulator.

Abstract: The multiple scattering of coherent radiation in an inhomogeneous medium is used to detect attempted intrusions into a protected area or into a tamper-proof package for such purposes as preventing the unauthorized detection and copying of electronic information used for authentication and coding in electronic commerce, communications, command, and control systems. A key advantage is that any intrusion into the sensed volume will produce a detected change in the measured intensity which will be equal to the full amplitude range if the intrusion is into a cylinder with radius comparable to the wavelength of the sensing radiation. The response of the medium can also be used to provide a unique identity key.

Abstract: A field disturbance sensor operates with relatively low power, provides an adjustable operating range, is not hypersensitive at close range, allows co-location of multiple sensors, and is inexpensive to manufacture. The sensor includes a transmitter that transmits a sequence of transmitted bursts of electromagnetic energy. The transmitter frequency is modulated at an intermediate frequency. The sequence of bursts has a burst repetition rate, and each burst has a burst width and comprises a number of cycles at a transmitter frequency. The sensor includes a receiver which receives electromagnetic energy at the transmitter frequency, and includes a mixer which mixes a transmitted burst with reflections of the same transmitted burst to produce an intermediate frequency signal. Circuitry, responsive to the intermediate frequency signal indicates disturbances in the sensor field. Because the mixer mixes the transmitted burst with reflections of the transmitted burst, the burst width defines the sensor range.

Abstract: An FM-CW radar transceiver comprising an oscillator connected to an input of a power divider having first and second terminal outputs. The first terminal output of the power divider is connected to an input of a first diode and a first shorted stub. The second terminal output of the power divider is connected to an input of a phase shifter with the output of the phase shifter connected to an input of a second diode and a second shorted stub. The outputs of the first and second diodes are each connected to inputs of first and second intermediate frequency (IF) filters and then through first and second IF blocking structures terminating at a common antenna port. An open stub is connected to the common antenna port with the outputs of the first and second IF filters each connected to an IF port or channel. In use, the FM-CW transceiver operates as a frequency multiplier for transmitting, and simultaneously as a subharmonically pumped "I/Q" mixer for reception.

Abstract: A filter for eliminating the effects of fluorescent lights on microwave transceivers uses a digital comb filter to eliminate signals at the AC power line frequency and its harmonics. A preferred embodiment has an A/D converter or sampler for sampling and digitizing an output signal from a microwave transceiver. The digitized signal is processed by a processor which implements the digital comb filter by performing a recursion equation. The inventive filter may also have a selector for selecting the sampling frequency. By selecting a desired sampling frequency, the filter may be easily adapted to filter out a different AC power line frequency. Thus, the inventive filter is easily adaptable for use in different countries having different AC power line frequencies.

Abstract: Doppler signals from a two-port radar system are spectrally processed and searched for a pattern of points wherein clutter at a first instant of time is subsequently replaced by low-level returns indicating the movement of a target. The rate of change of the low-level signals, along the same range bin but different Doppler bins, is indicative of target azimuth position relative to the boresight of the radar antenna. The difference between the total Doppler detected from the target and the Doppler for the azimuth position of the black hole detection is the Doppler for the relative radial velocity of the target. Not only is the black hole and shadow (lack of detection) detectable but more measurable and detectable is the clutter signal difference with the target motion.

Abstract: A motion sensing, micro-power impulse radar MIR impresses on the transmitted signal, or the received pulse timing signal, one or more frequencies lower than the pulse repetition frequency, that become intermediate frequencies in a "IF homodyne" receiver. Thus, many advantages of classical RF receivers can be thereby be realized with ultra-wide band radar. The sensor includes a transmitter which transmits a sequence of electromagnetic pulses in response to a transmit timing signal at a nominal pulse repetition frequency. A receiver samples echoes of the sequence of electromagnetic pulses from objects within the field with controlled timing, in response to a receive timing signal, and generates a sample signal in response to the samples. A timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver.

Abstract: A Doppler radar module constructed using micro-stripline technology is used in motion sensors and includes a local oscillator stabilized with a dielectric resonator that feeds a microwave antenna via a mixer that is connected in series. The transmission signal is emitted from the microwave antenna and is reflected back from an object where it is received by the antenna and forwarded to the mixer. The mixer mixes the reflected signal with a portion of the oscillator signal to form a Doppler signal.

Abstract: An autodyne motion sensor apparatus and method intended for use with automatic doors comprising, in a preferred embodiment, a phase coherent transceiver (11) incorporating dual demodulators in phase quadrature, means for amplification of the demodulated signals (12 and 13), means for converting the amplified demodulated signals to digital form (14 and 15) for input to a microprocessor, a microprocessor (16), provision for externally generated microprocessor interrupts corresponding to the instantaneous position of the door (17), provision for a uniform series of timing interrupts (18) to be applied to the microprocessor, provision for other microprocessor inputs a) characterizing the position and sense of motion of the door and b) parameter values utilized by the motion detection algorithm executed by the microprocessor, and a microprocessor detection signal output used to actuate the controlled door.

Abstract: An intrusion detection device of the dual sensing type has a PIR sensor to generate a PIR signal. The device also has a microwave sensor for generating a microwave amplitude signal. The microwave amplitude signal is filtered to generate a microwave high frequency signal which is the high frequency portion of the microwave amplitude signal. These three signals: PIR signal, microwave amplitude signal, and microwave high frequency signals are amplified and are digitized and are processed to generate an event signal. The event signal is compared to an event threshold signal and an alarm is generated in the event the event signal exceeds the event threshold signal. The event threshold signal represents the threshold to distinguish between a human intruder and an animal intruder.

Abstract: A simple, low power ultra-wideband radar motion sensor/switch configuration connects a power source and load to ground. The switch is connected to and controlled by the signal output of a radar motion sensor. The power input of the motion sensor is connected to the load through a diode which conducts power to the motion sensor when the switch is open. A storage capacitor or rechargeable battery is connected to the power input of the motion sensor. The storage capacitor or battery is charged when the switch is open and powers the motion sensor when the switch is closed. The motion sensor and switch are connected between the same two terminals between the source/load and ground.

Abstract: The invention relates to an electronic life detection system, in particular for the searching for buried persons and the surveillance of buildings, having a microwave transmitting/receiving device for generating and radiating microwaves into an area to be investigated and for registering the microwave signal reflected from the area under surveillance and modulated with the frequencies corresponding to the life functions of any living beings present in the area, which device has a first signal-conditioning device, and a second signal-conditioning device.

Abstract: A radar system which detects the presence of objects in the proximity of a movable vehicle includes a signal source which generates object detection signals, a first antenna which transmits the object detection signals and receives the object detection signals as reflected signals reflected from an object in the proximity of the movable vehicle. The first antenna is further operable for receiving non-reflected test signals. A second antenna is provided for transmitting test signals which correspond to a delayed portion of the object detection signal generated by the signal source. A control unit is responsive to the reception of the reflected signals for providing an indication of the detection of the object, and is responsive to the reception of the test signals for providing an indication of the operability of the system.

Abstract: The invention provides a method and a system for the detection of an object moving relative to another object. The object possibly being a person, an element, an installation, a tool, a surface, etc. According to the invention, a UHF wave is generated in a slotted antenna and the rays exiting from the slots are directed onto the area to be monitored. The reflected waves are detected and this frequency is compared with the frequency of the transmitted waves.

Abstract: The microwave section of a dual technology sensor comprising microwave and infrared sections may be periodically tested. This is done by arranging for the output of the microwave section to be monitored at times corresponding to microwave pulses and at times coresponding to no microwave pulses. If the microwave section is operating properly then a difference should be seen in the output between the "pulse" and "no pulse" times. Because this test can involve a change in the average energy output by the microwave section it can also affect the infrared section of the sensor which often inadvertently receives radiation from the microwave source. Thus the infrared section may be tested using this effect.

Abstract: A method for activating a mine possessing a specified activation radius; in particular an anti-helicopter mine, which is brought into an alarm condition by acoustic signals. In the alarm condition of the mine, an NLOS-radar is activated, through which the target speed and the target range of a helicopter are detected and the result of the detection is compared with the specified activation radius of the mine. Full activation of the mine is then implemented when the detection result is smaller than the activation radius, or a further or renewed NLOS-radar detection is effected when the detection result is greater than the activation radius of the mine.

Abstract: A motion detection radar system comprised of a low power frequency tunable continuous wave transmitter and antenna, a receiver, an FM transmitter and antenna, and a handheld remote FM receiver. The radar system may be adapted to operate at any frequency from 600 MHz to 1.2 GHz. The motion detecting radar system uses a technique for measuring the changes in phase difference and the rate of change of phase differences detected thereby. The receiver captures the total energy reflected from all reflective objects within the antenna field of view and compares that signal with the transmitted signal in a mixer. If all objects are stationary and the radar system is stationary, the total complex phase pattern of the return signal is constant, and a fixed DC output signal is provided from the mixer. Any motion within the field of view changes the fixed phase relationship and causes a phase rate of change at the receiver output.

Abstract: In a vehicle presence detection system for controlling traffic signal lights at a road intersection, the vehicle detection is performed by targeting vehicles at the location of interest with an FMCW radar beam. The radar can be switched repeatedly between the FMCW mode, for vehicle presence detection, and a doppler mode, for vehicle movement detection. Signal data representing the background of the scene viewed by the radar beam are stored for use by circuitry that determines whether an apparent vehicle presence detect is a true vehicle detect; the background signal data is repeatedly updated, as necessary, as the system cycles. Temperature compensation is provided and entry into the FMCW mode is inhibited if a voltage-controlled oscillator provided for generating the emissions has not settled down after any such compensation.