Abstract: A system and technique for mounting a radar to a vehicle provides a mounting that does not interfere with the aesthetic appearance of a vehicle, that does not interfere with the aerodynamic performance of the vehicle, and offers optimal radar transmission efficiency. The vehicle can be an automobile or any other vehicle to which a radar system is applied.

Abstract: An edge concealment system for abating electrical discontinuities between externally exposed edges of adjacent surface pieces separated by a gap. The system includes a cover component shrouding each edge and able to absorb or conduct incident radar energy. A male element and a female element extend between the cover component and the surface piece for positive engagement of the male element within the female element and retention of the cover component with the surface piece. Preferably the engagement of the male and female elements includes an audible signal such as a click sound when the engagement occurs so that operators are confirmatively advised upon positive placement.

Abstract: A vehicle (160) such as a motor road vehicle is fitted with an electromagnetic sensor system comprising transmitting means (e.g. 4, 1) for transmitting a radio frequency signal, receiving means (e.g. 2, 6) for receiving reflections of said signal from remote objects, sampling means (20, 28) operable to sample the received reflected signal (or a signal derived therefrom), and processing means (e.g. 36) for processing the sampled signal, and operable to detect said reflections in the sampled signal, and to determine information on the presence, position and/or range of said object. The system includes filter means (e.g. 34) for preventing radio signals transmitted by other sources or noise spikes from causing interference which results in spurious detections or indications of range by the processing means.

Abstract: A system and technique for mounting a radar to a vehicle provides a mounting that does not interfere with the aesthetic appearance of a vehicle, that does not interfere with the aerodynamic performance of the vehicle, and offers optimal radar transmission efficiency. The vehicle can be an automobile or any other vehicle to which a radar system is applied.

Abstract: This invention concerns a repeater jamming transmitter (2), and a casing arrangement with repeater jamming transmitter. The repeater jamming transmitter (2) comprises transmitter antenna (7), receiver antenna (8) and electronics part (10) with amplifier and control circuits. In order to avoid self-oscillation caused by leakage between the transmitter antenna (7) and the receiver antenna (8) and to maintain the isolation a special connection arrangement (7,8,10) is included in the repeater jamming transmitter. By means of the connection arrangement the amplification of the repeater jamming transmitter can be increased without self-oscillation arising.

Abstract: A device to conceal a radar fitted into an automobile comprises at least one system of conductive wires perpendicular to the polarization of the wave sent out by the radar and reproducing a given graphic representation The graphic representation may be the automobile manufacturer's logo. The disclosed device can be applied especially to radars positioned in from of vehicles, for example of the ACC type.

Abstract: A radar signal detecting apparatus is provided. The radar signal detecting apparatus includes a coupler diverging a part of signal from received signal, a local oscillator outputting local signal, a mixer converting the diverged signal multiplied the local signal into low frequency signal and a detector detecting a radar signal from the low frequency signal by using a threshold above side lobe.

Abstract: A low power radar level transmitter having reduced ground loop errors and a related method are disclosed. A microwave termination is couplable to a reference voltage such as earth ground and is coupled to a microwave transceiver through at least one low frequency isolator. The microwave transceiver generates a microwave signal along the termination which is reflected by a process product interface. A level calculator is coupled to the microwave transceiver to calculate a level of the process product based upon the received, reflected signal. A process loop communicator is coupled to the level calculator and couplable to a process control loop to communicate the calculated level across the process control loop. A power supply is couplable to the process control loop and provides power to all electrical components of the transmitter with energy received from the process control loop.

Abstract: A novel method of creating and detecting ultra wide bandwidth signals in a ground penetrating radar context.

Abstract: The invention relates to a multi-face phased array antenna. To prevent crosstalk between the individual faces, each face comprises two cancellers, each of which cancels the crosstalk from an adjacent face. To this end, each canceller receives a reference signal from an adjacent face and is provided with a quadrature mixer and a vector modulator.

Abstract: A technique for operating a communication link in RF proximity to an operational radar. A data link waveform is employed which allows a data link receiver to detect an alert indication during normal radar operation. When the alert is detected, the system briefly inhibits radar operation to receive the information content of the data link message. A data link message rate is selected to keep the impact to radar operation at a minimum.

Abstract: A procedure and a system increase the performance of a group of radar units. The radar units are arbitrarily located in such a way that the respective antenna beam of a radar unit functioning as a normal radar at least partially coincides with the antenna beam of at least one other radar unit in the group. The radar units are synchronised to transmit alternately and in turn, preferably with an increased energy output. All the radar units in the system are synchronised to work continuously in their ordinary reception mode. In this way at each moment echo signals originating from the radar unit transmitting at that moment are received and processed.

Abstract: A single antenna poly-frequency Continuous Wave (CW) Doppler radar system having leakage cancellation. The system provides for transmitting a plurality of carrier frequency signals and receiving the return signals by means of a single antenna coupled to an antenna interface through which a portion of the transmitted signal may leak. The signal appearing on an output port of the antenna interface is then down-converted to an intermediate frequency (IF) signal by a stable mixing signal. The IF signal is coupled to an adder which in turn is coupled to an output. The IF signal is further split into a pair of cancellation loops for each carrier frequency signal.

Abstract: A radar transponder for a stable and reliable response transmission upon reception of a weak radar signal having a reflection-conscious circuitry free from damage by a transmit effect, including a reception damage by the leakage of a powerful transmit wave signal and a transmission damage by the reflection of the powerful transmit wave signal. The reflection-conscious circuitry may include a circulator coupled to the transmit/receive antenna for selecting the powerful transmit wave signal or the weak radar signal, a receiving circuit provided after the circulator for receiving the weak radar signal, and an SPDT switch provided between the circulator and the receiving circuit for passing an input of the weak radar signal to the receiving circuit in a receiving period with its ground function dormant and for leading an input of the powerful transmit wave signal to a ground using the ground function in a transmitting period.

Abstract: An aircraft mounted pulse radar unit transmits a low-energy, test output pulse and processes the resulting test return signal to determine the VSWR and whether the VSWR exceeds a predetermined threshold. If the VSWR exceeds the threshold, the unit prevents transmission of a nominal energy output pulse which might result in damage to the receiver due to an excessive energy level of the return signal. In one embodiment, the unit uses the VSWR to determine and enable output signals at reduced power levels such that energy levels of any return signals would be insufficient to damage the receiver.

Abstract: A radar system having a radar transmitter and a radar receiver. The radar receiver includes a "local" receiving station and a "remote" located antenna station. A feedthrough nulling system is provided. The nulling system includes a "remote" combiner for providing an feedthrough null residual signal representative of the difference in power between a signal received by the antenna station and a feedthrough nulling signal. A "remote" downlink modulator, disposed at the antenna station, produces an optical signal representative of the feedthrough null residual signal. A "local" downlink optical detector, disposed at either the receiver station or the transmitter, detects the optical signal representative of the feedthrough null residual signal.

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: Microwave devices incorporate at least one photosensitive baffle that is selectively illuminated changing the baffle's electronic characteristic from being transparent to being reflective of microwave energy. The baffle serves as a gate, tuning element, reflector and the like. Various forms of photosensitive baffles and microwave devices are presented.

Abstract: A switching device is provided which uses an array of high-speed photoconductive semiconductor switches laid out in a stripline configuration to achieve a transmitter-to-receiver isolation sufficient to support a monostatic configuration for a high-power, monostatic impulse radar.

Abstract: A Reduced Radar Cross-Section RF Seeker Front-End interrogates a potential arget by issuing interrogation radiation toward the target and receiving and analyzing a portion of the radiation that reflects back from various surfaces of the targeted object while, at the same time, the Front-End reduces the likelihood of its own discovery by the enemy. The Front-End accomplishes the reduction by absorbing radiation directed toward it by an enemy radar or anti-tactical missile rather than allowing the radiation to be reflected back. Such absorption greatly diminishes the availability of signature reflection that belligerents rely on to identify hostile forces on the battlefield.

Abstract: An apparatus and method are provided for continuously and automatically protecting an electrical device (22) from a potential threat of damaging voltage levels. The apparatus includes a detector (24) for the threat and a protection switching circuit (30) for grounding the electrical device and the detector upon detection. Grounding occurs for a predetermined time interval, after which the detector is again automatically re-activated. Embodiments of detectors include detectors which detect the degree of electrical changes in a surrounding field and detectors comprising a tuned radio receiver. One embodiment includes a device utilization monitor (222) and a detector disable circuit (224) for disabling the detector, and thereby precluding grounding, while a device such as a radio frequency transmitter is being utilized.

Abstract: A device for use as a receiver protector in radar systems comprising a passive gas stage device and a waveguide opening. The passive gas stage device includes a sealed quartz container, a reactive gas filling the container and a thin film of radioactive material deposited on a flat surface of a glass rod in the interior quartz container for providing free electrons to initiate a gas discharge in the presence of high power pulses. The waveguide opening includes an iris plate having a discharge gap that is in close proximity to the film of radioactive material so that the film provides a large number of electrons in the discharge gap to initiate a gas discharge in the presence of microwave pulses.

Abstract: An integrated circuit configurable as a transmitter/receiver includes learn capabilities that allows a receiver IC to memorize the identification pattern of a specific transmitter.

Abstract: Disclosed is device with high linearity for limitation of a characteristic of a signal to a maximum value S.sub.max, and notably the amplitude of a radar signal in a reception system with high linearity. The device comprises a limiter having a limitation threshold S.sub.lim that can be switched over to two possible values S.sub.h and S.sub.b chosen so as to be respectively higher and lower than S.sub.max and means to activate the switching over of the limitation threshold S.sub.lim to either one of the foregoing values, depending on whether a measurement representing a characteristic of the signal such as the amplitude delivered by measurement means is higher or lower than a given comparison threshold V.sub.H. A device such as this is very useful in a radar reception system with high linearity carrying out an analog-digital encoding of the radar signal, for it protects the encoder used from saturation with a minimum lowering of performance characteristics in terms of dynamic range and linearity.

Abstract: A microwave repeater with antenna isolation comprises a first receiving anna for receiving an input signal from a distant source; an amplifier section for amplifying and modulating the input signal to produce an output signal; a transmitting antenna coupled to the amplifier section; and an isolation control means including a second receiving antenna for isolating the first receiving antenna from the transmitting antenna. In one preferred embodiment, the second receiving antenna is aligned so as to match the gain and phase from the transmitting antenna to the first receiving antenna. The isolation control means comprises a phase shifter coupled to the second receiving antenna; and a power combiner having inputs coupled to the first receiving antenna and the phase shifter and an output coupled to the amplifier section. The power combiner receives the input signal from the first receiving antenna and a 180.degree. phased shifted signal from the phase shifter.

Abstract: A monostatic frequency modulator continuous wave radar for detecting and determining the distance to near range objects. A temperature compensated one port Z-network is provided to generate a voltage of equal magnitude and opposite sign to that of the voltage reflected from the antenna.

Abstract: An apparatus and method are provided for continuously and automatically protecting an electrical device (22) from a potential threat of damaging voltagelevels. The apparatus includes a detector (24) for the threat and a protection switching circuit (30) for grounding the electrical device and the detector upon detection. Grounding occurs for a predetermined time interval, after which the detector is again automatically re-activated. Embodiments of detectors include detectors which detect the degree of electrical changes in a surrounding field and detectors comprising a tuned radio receiver. One embodiment includes a device utilization monitor (222) and a detector disable circuit (224) for disabling the detector, and thereby precluding grounding, while a device such as a radio frequency transmitter is being utilized.

Abstract: A continuous wave radar system comprises a transmitter section (1), a receiver section (2) and a common transmit/receive aerial (3). A directional coupler (12) is used to couple the transmitter section output (9) to the aerial (3) and to couple the aerial (3) to a first input (5) of a mixer (4) included in the receiver section (2). A second input (6) of the mixer (4) is fed with a reference signal from the transmitter section (1) via a fourth port (17) of the coupler (12), thereby usefully utilizing at least some of the transmitter power which would be wasted were the fourth port (17) merely terminated in a matched impedance.

Abstract: A method and apparatus for suppressing leakage spikes in a radar duplexer. A flash of radiant energy is triggered immediately prior to sending a radar pulse so as to ionize the gases in a duplexer tube before the leading edge of the radar pulse reaches the tube. The spike suppressor includes an radiant energy source which attaches to the radar duplexer so that the source shines into the duplexer tube. A pulse generator is provided for activating the source in response to a trigger signal.

Abstract: A gain control network having a phase splitter circuit responsive to an RF input signal for providing first and second RF signals that are out of phase relative to each other, a first series of switched gain control elements, and a second series of switched gain control elements substantially identical to the first series and commonly controlled therewith. The first series of gain control elements is responsive to the first RF signal for providing a first gain controlled signal, and the second series of switched gain control elements is responsive to the second RF signal for providing a second gain controlled signal. A phase combining circuit combines the first and second gain controlled signals to provide a gain controlled RF output. By performing gain control with two gain control channels having substantially identical circuits and common switching control, transient glitches in each of the channels are substantially identical and are substantially cancelled via the phase combiner.

Abstract: An optical ranging system includes optics that create a backscatter signal in response to a transmitted light pulse. The transmitted pulse is reflected from a target to provide range information. The backscatter signal is applied to trigger a threshold detector. The output of the threshold circuit is applied to a delay circuit to provide a receiver switch control signal which renders a receiver switch conductive after the backscatter signal. Accordingly, the receiver switch blanks the backscatter signal and applies the reflected signal to the receiver.

Abstract: Apparatus for isolating a radar receiver from a radar transmitter in a continuous wave, single antenna radar system where a circulator connects transmitter, receiver, and antenna. The apparatus includes a reactive element which reflects back through the circulator a portion of a transmission signal provided from the transmitter through the circulator to the antenna. The reflected transmission signal portion is equal in magnitude and opposite in phase to a leakage portion of the transmission signal transmitted by the circulator from the transmitter to the receiver. The reflected and leakage signal portions cancel in the circulator to enhance the isolation of the receiver.