Abstract: In a radio wave radar system using a two-frequency CW modulation method, it is possible to detect a distance between a host vehicle and a forward vehicle and to realize a stable ACC following travel, even in a condition in which the relative speed is 0. By combining the two-frequency CW modulation method with the frequency pulse CW modulation method, that is, by using combination with the two-frequency CW method when the relative speed occurs and the frequency pulse CW method when the relative speed is close to 0, even if the relative speed is 0, the IF signal obtained from the reflected wave from the forward vehicle can be generated to detect the existence of the ACC target vehicle, so that it is possible to realize a stable ACC following travel.

Abstract: A radar apparatus includes: a modulation signal generating circuit that generates a modulation signal; a carrier wave generating circuit that generates a carrier wave; a modulation circuit that outputs a high frequency signal generated by modulating the carrier wave using the modulation signal that has been inputted; a modulation signal extracting circuit that extracts the modulation signal from the high frequency signal that has been inputted; and a detection signal generating circuit that generates a detection signal, which can be used to measure a distance to a measured object, based on the modulation signal extracted by the modulation signal extracting circuit from a component, out of the high frequency signal that has been transmitted via a transmission antenna, the component having been reflected by the measured object and received by a reception antenna.

Abstract: The synthesizer and method provide a relatively wideband swept frequency signal and include generating a first swept frequency signal with a first generator, and successively switching between different frequency signals with a second generator. Such switching creates undesired phase discontinuities in the output swept frequency signal. The first swept frequency signal is combined with the successively switched different frequency signals to produce the relatively wideband swept frequency signal, and the second generator is calibrated to reduce the undesired phase discontinuities during switching based upon the output swept frequency signal.

Abstract: The invention relates to remote distance measurement by means of a transmitted noise modulated probing signal (E), whereby at least one of a distance (Y(t)) and a velocity (V(t)) in relation to a signal transceiver (200) is determined. The probing of signal (E) is generated on basis of at least one first noise signal (x1(t), x2(t)). The transmitted signal (E) is presumed to be reflected to the signal transceiver (200) via at least one signal reflecting object in the form of an information carrying signal (e). This signal thus constitutes a delayed and possibly doppler shifted version of the transmitted signal (E). Moreover, according to the invention, a second noise signal (x2(t)) is added either to the probing signal (E) before it is transmitted or to the information carrying signal (e) before information pertaining to the reflecting object is derived there from.

Abstract: In order to refine a device and a method for registering, detecting, and/or analyzing at least one object, a registration range and/or at a detection gate being displaced at a scanning speed over a measuring range, in such a way that a target-unique velocity measurement is ensured in continuous detection operation with low latency time and resistance to fluctuations, it is provided that, the receive circuit be divided into at least two channels, which are operable separately from one another, in particular using at least one power divider unit connected downstream from the output terminal of the I/Q mixing unit, of which the first channel of the receive circuit is designed for the purpose of displacing the registration range and/or the detection gate at a constant scanning speed over the entire measuring range, and the second channel of the receive circuit is designed for the purpose of displacing the registration range and/or the detection gate at a variable, in particular reducible scanning speed over the m

Abstract: An embodiment comprises a unit generating a control pulse signal by delaying a basic signal in generating a transmission pulse, and a unit performing a gate operation on a received signal using the control pulse signal. Another embodiment comprises a unit generating a control pulse signal by delaying a signal generated using a first basic signal, a second signal for phase modulation having a lower frequency than the first signal, and a pseudo-random signal generated at an intermediate frequency between the frequencies of the first and second signals, and a unit performing the gate operation.

Abstract: A millimeter wave pulsed radar system includes a radar synthesizer having a voltage controlled oscillator/phase locked loop (VCO/PLL) circuit, direct digital synthesizer (DDS) circuit and quadrature modulator circuit that are operative to generate an intermediate frequency local oscillator signal (IF/LO signal). A radar transceiver is operative with the radar synthesizer for receiving the IF/LO signal. A transmitter section has a frequency multiplier that multiplies the IF/LO signal up to a millimeter wave (MMW) radar signal and a receiver section and includes a direct conversion mixer that receives a MMW radar signal and the IF/LO signal to produce I/Q baseband signals that are later digitized and processed.

Abstract: Methods and apparatus are provided for radar systems using multiple pulses that are shorter than the expected range delay extent of the target to be imaged. In one implementation, a method for performing radar includes the steps of: transmitting a plurality of pulses, each pulse having a different center frequency and a time duration shorter than an expected range delay extent of a target, wherein a total bandwidth is defined by a bandwidth occupied by the plurality of pulses; receiving reflections of the plurality of pulses; and performing pulse compression on the received pulse reflections to generate a detection signal having a radar resolution approximately equivalent to the transmission and reception of a single pulse having the total bandwidth. In preferred form, the pulses comprise ultrawideband (UWB) pulses each occupying a sub-band of the overall system bandwidth.

Abstract: A stepped-frequency chirped waveform improves SAR groundmapping for the following reasons. Range resolution in SAR image is inversely proportional to the transmitted signal bandwidth in nominal SAR systems. Since there is a limit in the transmitted bandwidth that can be supported by the radar hardware, there is a limit in range resolution that can be achieved by processing SAR data in conventional manner. However, if the frequency band of the transmitted signal is skipped within a group of sub-pulses and received signal is properly combined, the composite signal has effectively increased bandwidth and hence improvement in range resolution can be achieved. The proposed new and practical approach can effectively extend the limit in range resolution beyond the level that is set by the radar hardware units when conventional method is used.

Abstract: To provide a radar system mounted on a vehicle that reliably detects the reception of the interference wave with high-performance and inexpensively. There is provided a radar system mounted on a vehicle for detecting a target object, including a transmitter for transmitting an electromagnetic wave, a receiver for receiving the electromagnetic wave reflected by the target object, a signal processor for measuring a distance between a vehicle of his/her own and the target object and a relative velocity on the basis of the transmitting electromagnetic wave and the receiving electromagnetic wave, and an interference detector for suspending a transmit operation of the transmitter under a control of the signal processor to detect an interference signal from another external device.

Abstract: The distance and relative speed of an object remote from an observation point determined using a signal form which includes two signals having a predetermined spacing relative to each other. The two signals are transmitted for a certain time interval during which the frequency of the signals is modulated in a stepwise fashion. Additionally, the signal sections of the two signals are transmitted alternately for each step so that there is a predetermined frequency spacing between the signal sections being emitted consecutively.

Abstract: A radar, sonar, lidar or like active detection, tracking system calculates the clutter which would occur with various different transmit waveforms, and selects from among those waveforms that one which, given the current clutter, is expected to minimize variation or variability of the clutter. The calculation is performed by generating a clutter kernel for the current transmitted or other reference waveform, and calculating the clutter which would result with alternate transmit waveform(s). The variability of the various clutter responses is determined, and the transmit waveform exhibiting the least clutter variability is selected for a later transmission.

Abstract: A pulse radar device includes a rectangular signal generating section for generating a rectangular signal that is a reference signal; a transmit timing voltage setting section for setting a voltage value for determining a transmit timing; a transmit pulse generating section for generating a transmit pulse based on the rectangular signal and the voltage value; a receive section for receiving a reflection wave obtained by reflecting the electric wave transmitted by the transmit section by a plurality of objects; a receive saw-tooth wave generating section for generating a saw-tooth wave in synchronism with the transmit pulse; a receive signal sample hold section for sample-holding the receive signal based on the outputs from the saw-tooth wave and the rectangular signal; and a detecting and distance measuring section for detecting the objects and measuring a distance to the objects based on the sample/hold output.

Abstract: A pulse radar device includes a VCO that oscillates a carrier wave that has been modulated in frequency, a switch that modulates the carrier wave generated by the VCO to a pulse wave, a transmission antenna that transmits the pulse wave that has been modulated by the switch as an electromagnetic wave, a reception antenna that receives a reflection wave obtained by reflecting the electromagnetic wave that has been transmitted by the transmission antenna by a target substance, a mixer that demodulates the reception signal that has been received by the reception antenna on the basis of the carrier wave that has been generated by the VCO, and a limiter that limits an amplitude of the demodulation signal which has been demodulated by the mixer.

Abstract: A pulse radar system has a high-frequency source, which supplies a continuous high-frequency signal and is connected on the one side to a transmission-side pulse modulator and on the other side to at least one mixer in at least one receive path. A pulse modulator is connected upstream of the mixer with regard to its connection to a receiving antenna. The mixer evaluates a radar pulse reflected by an object together with the signal of the high-frequency source. This system does not require a ZO switch and is insensitive to interference.

Abstract: A radar device is described having means (12) for generating a first code, means (18) for modulating a transmission signal in a transmitting branch using the first code, means (32) for delaying the first code, means (20) for modulating a signal in a receiving branch using the delayed first code, and means for mixing a reference signal with a reception signal, multiple receiving channels (111, 112, . . . 11k) being provided, the receiving channels (111, 112, . . . 11k) having means (1201, 1202, . . . 120k) for generating additional codes (C1, C2, . . . Ck), the receiving channels (111, 112, . . . 11k) having means (131, 132, . . . 13k) for demodulating using the respective additional codes (C1, C2, . . . Ck), and means (15) being provided for modulating the transmission signal using at least one of the additional codes (C1, C2, . . . Ck). A method which may be implemented advantageously using the radar device described is also described.

Abstract: A double side band diplex linear frequency modulated superimposed radar system determines the range of targets as a function of the amplitude variation of reflected target Doppler signals. The present invention includes a real radar system that accurately determines the range of fading targets and the magnitude of the velocity of the targets. The present invention also includes a complex radar system that determines the relative velocity of targets in addition to the range of targets. The present invention also includes a real radar system having BPSK modulation. The selection of BPSK modulation enables or facilitates. the implementation of a portion of the system in digital form.

Abstract: A pulse radar device includes a VCO that oscillates a carrier wave that has been modulated in frequency, a switch that modulates the carrier wave generated by the VCO to a pulse wave, a transmission antenna that transmits the pulse wave that has been modulated by the switch as an electromagnetic wave, a reception antenna that receives a reflection wave obtained by reflecting the electromagnetic wave that has been transmitted by the transmission antenna by a target substance, a mixer that demodulates the reception signal that has been received by the reception antenna on the basis of the carrier wave that has been generated by the VCO, and a limiter that limits an amplitude of the demodulation signal which has been demodulated by the mixer.

Abstract: A radar system having an arrangement for producing a code, an arrangement for modulating a transmission signal in a transmit branch, using the code, an arrangement for delaying the code, an arrangement for modulating a signal in a receive branch, using the delayed code, and an arrangement for mixing a reference signal with a receiving signal, the modulation of one of the signals being performed by an amplitude modulation (ASK; “amplitude shift keying”) and the modulation of the other signal by a phase modulation (PSK; “phase shift keying”). Furthermore, a radar system is proposed in which blanking of phase transitions is provided. Also described are methods which may advantageously be carried out, using the radar systems described herein.

Abstract: In a method for HPRF-radar measurement of the range and Doppler frequency of at least one target, a transmit signal is generated which consists of two pulse sequences that are interleaved on a pulse to pulse basis, and have the same pulse repetition frequency PRF and the same transmit frequency. The pulses of a first one of the two pulse sequences have a linearly increasing phase value with a fixed phase difference &phgr;1n (greater than zero) from pulse to pulse with &phgr;1n≧0, while the pulses of the second pulse sequence have a linear increasing phase value with a fixed phase difference &phgr;2n which differs from &phgr;1n. The two received base band signals of each individual pulse sequence are Fourier transformed, and the amplitude peaks of the resulting two Fourier spectra are determined.

Abstract: An FM-CW radar processing system pairs up peaks obtained by fast-Fourier transforming a beat signal occurring on an up portion and a down portion of a triangular-shaped FM-CW wave, calculates a distance or relative velocity with respect to a target object based on the peak signal in the up portion and the peak signal in the down portion obtained by the pairing, and compares the distance or relative velocity, obtained after changing the modulating signal for the FM-CW wave, with the distance or relative velocity obtained before changing the modulating signal. If the distance or relative velocity differs before and after changing the modulating signal, the pairing is judged to be mispairing.

Abstract: The present invention relates to a radar device and, particularly, to a radar device mounted on a vehicle to be used for a collision alarm and the like. The invention provides a radar device that has a unit for removing the FMAM noise without lowering the signal detection sensitivity. The radar device transmits a frequency modulation signal by switching the frequency modulation signal with a first switching signal, receives a signal reflected from a target object, switches the reception signal with a second switching signal, mixes the switched reception signal with the transmission signal, and further mixes the mixed signals with a third switching signal thereby to obtain a beat signal. The radar device obtains a distance to the target object and a relative speed of the target object from the beat signal.

Abstract: As to a beat signal of a received wave, for instance, a plurality of FFT-based frequency spectra of every FM rise zone are accumulated in an accumulation unit. A judgment unit judges a valley section from the plurality of frequency spectra accumulated. A peak frequency extraction unit acquires, as beat frequencies of different targets, respective beat frequencies of peak sections located at both sides of the valley sections judged.

Abstract: The determination of separation (R) and relative speed (v) of at least one object which is distant from an observation point can be achieved by sending electromagnetic signals from the observation point, with a frequency shift over a modulation range (fSweep), in the form of signal segments (A, B) during a measuring interval, with a frequency separation (fShift) from each other which are transmitted alternately, the echo signals from which are detected after reflecting from the object. The phase difference (&Dgr;&phgr;) of the echo signals arising from each signal segment (A, B) is detected. Said determination occurs with short reaction time and high precision whereby the signal segments (A, B) are transmitted with a stepwise shift each time by a frequency step (fIncr) over the modulation range (fSweep) and at least one sampled value for determination of the phase difference (&Dgr;&phgr;) for each signal segment is taken.

Abstract: A pulse-type beamforming apparatus, such as a radar array system, is used for receiving, detecting, localizing, and/or imaging desired signals. The apparatus is used to receive wideband chirp signals. The apparatus contains a receive aperture that is partitioned into multiple channels. The received signal at each channel is mixed with a replica chirp. The replica chirp is effectively delayed in a way that partially removes range-dependent distortion of desired signals. The mixer outputs are then sampled and filtered. The filters on each channel incorporate a time delay that completely removes the remaining range-dependent distortion for all signals in a desired direction. Signals are also compressed and integrated by a digital beamformer.

Abstract: The present invention relates to a radar system having means (12) for producing a code, means (18) for modulating a transmission signal in a transmit branch, using the code, means (32) for delaying the code, means (20) for modulating a signal in a receive branch, using the delayed code, and means (26) for mixing a reference signal with a receiving signal, the modulation of one of the signals being performed by an amplitude modulation (ASK; “amplitude shift keying”) and the modulation of the other signal by a phase modulation (PSK; “phase shift keying”). Furthermore, a radar system is proposed in which blanking of phase transitions is provided. The present invention also relates to methods which may advantageously be carried out, using the radar systems according to the present invention.

Abstract: A method and an apparatus for multiple object detection by automotive FMCW radars provides distance and relative velocity information. A two chirp frequency sweep with small slope difference is utilized and, since the difference is small, the distance information can be obtained by automatically eliminating the Doppler frequency. Therefore, the distance and the relative velocity information for each of multiple objects can be calculated without ambiguity.

Abstract: System for measuring the distance and the relative speed between objects using electromagnetic waves, having means for emitting electromagnetic waves from a first object and having means for receiving reflected electromagnetic waves from at least one second object, the frequency of the emitted signal being modulated in such a way that the modulation frequency, during a first time segment, increases approximately linearly from a first to a second modulation frequency value, that the modulation frequency, during a second time segment, is approximately constant, that the modulation frequency, during a third time segment, decreases approximately linearly from the second to a third modulation frequency value, that the modulation frequency, during a fourth time segment, is approximately constant, and that these time segments recur repeatedly, at least one of the modulation frequency values and/or the duration of at least one time segment being changeable.

Abstract: In an FM-CW radar apparatus, while a distance and velocity of a target are measured by simultaneously transmitting an FM modulation wave along a frequency-up direction and an FM modulation wave along a frequency-down direction toward this target, physically-required radar signal measuring time thereof can be reduced by ½.

Abstract: A wideband adaptive digital beamforming technique for maintaining a high range resolution profile of a target in motion in the presence of jamming utilizes a sequence of adaptively calculated narrowband jamming cancellation weights. The adaptive weights are calculated such that the desired frequency dependent gain is maintained toward the target center. These adaptive weights tend to preserve the range profile quality and low range sidelobes. This technique also tends to eliminate signal cancellation problems as well as adaptive weight modulation effects.

Abstract: An association method for a multi-slope FMCW radar identifies candidate combinations of frequency components as being correctly or incorrectly associated based on calculated range-rate. Range and range-rate are calculated for various pairs of frequency components emanating from like-polarity slopes of the transmitted waveform, and pairs having similar ranges and range-rates are combined to form candidate associations. The range and range rate of the candidate associations are then computed using all four frequency components, and ambiguous candidate associations are resolved by selecting the candidate associations having similar range rates.

Abstract: The invention relates to a method for measurement of the radar target cross section of an object with both moving and fixed parts, which method comprises a first measurement with high frequency resolution, from which information can be extracted on modulations in the signal received that derive from moving parts of the object and fixed parts of the object respectively. The invention is characterized in that the method comprises a second measurement with high range resolution, and filtering of the measuring result obtained from the second measurement, which filtering is performed around a certain frequency that is obtained by means of the measuring result from the first measurement. The first measurement is preferably given a high frequency resolution in that it is performed with a narrow-band waveform, and the second measurement is suitably given a high range resolution in that it is performed with a broadband waveform.

Abstract: The present invention relates to a CW radar method for measuring distances between and relative speeds of a vehicle and one or more obstacles. The present invention further provides that the transmission (s(t)) can be composed of at least four consecutive chirps (A, B, C, D), each having different slopes. The intersection points of all lines in the distance-relative speed diagram from two chirps (A, B) can be calculated from all the ascertained frequency positions K1,n and K2,p. To validate those intersection points, one may observe whether a peak exists in the Fourier spectrum of a third chirp C at a frequency position K3,q, whose assigned line intersects a surrounding area of the intersection point in the distance-relative speed diagram.

Abstract: A random pulse type radar apparatus sends out as an output signal a spectrum spread radio wave including a pseudo random signal-less period and receives echoes in this signal-less period to thereby significantly reduce transmission peak power.

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 heterodyned double side band diplex radar system determines the range of targets as a function of the amplitude variation of reflected target Doppler signals. The present invention includes a real radar system that accurately determines the range of fading targets and the magnitude of the velocity of the targets. The present invention also includes a complex radar system that determines the relative velocity of targets in addition to the range of targets. In either embodiment, the transmitted signal may be modulated with a pseudo-random number (“PN”) sequence to attenuate or decorrelate signals reflected from targets beyond some maximum range. The modulation of the pseudo-random sequence may also attenuate or decorrelate signals reflected from targets closer than some minimum range. The present invention also includes a real radar system having BPSK modulation with PN coding. The selection of BPSK modulation enables or facilitates the implementation of a portion of the system in digital form.

Abstract: A pulse radar system includes a frequency-agile magnetron comprising an input for giving a feeding voltage of a magnetron tuner. A modulator connected to said magnetron forms pulses of a feeding voltage for the magnetron. A low power signal source also connected to said magnetron generates microwave frequency signals which are given to the magnetron in pauses between pulses. These signals have the frequencies differing from the frequencies of the signals generated by the magnetron and fixed during each period of magnetron pulse repetition. This radar system also includes a signal converter receiving the low power signals reflected by the magnetron. These signals are converted into the signals connected in time to the moments, when the frequencies of the low power source and the frequencies of the magnetron oscillating system coincide with each other. Further, said signals are used for triggering the modulator connected to said converter.

Abstract: Microwave radar: an additional modulation of the microwave signal (s (t)) provided for the emission or of the reception signal (e (t)) makes it possible to separate the payload signal from the noise signal parts in a following demodulation and filter unit (HP, MI2, TP). To this end, a modulation unit (MO, RG) for suitably modulating the signal to be emitted is provided preceding the antenna (A). The undesired noise signals produced by the components of the radar sensor itself are not modulated and can therefore be separated from the payload signal by filtering. This separation ensues after a raw measured signal (mess' (t)) has been generated by mixing transmission and reception signal (MI). A renewed demodulation with the modulation signal (r t)) of the modulation unit supplies the final measured signal (mess2 (t)) determinant for the determination of the distance, whereby the noise signals are previously removed by high-pass filtering and/or are subsequently removed by low-pass filtering.

Abstract: A method provides for contactless measurement of the range between a transceiver unit for microwaves in the frequency band from 1 to 100 GHz and an object to be investigated using a pulse principle. The microwaves are focused onto the surface by an antenna to detect the contour of the object. In particular, the surface of a bolt produced using a spray compacting method can be detected.

Abstract: An FM-CW radar apparatus is provided which may be employed in automotive anti-collision or radar cruise control systems. The radar apparatus transmits as a radar wave a high-frequency signal which is so modulated in frequency with a modulating signal as to vary with time in the form of a triangular wave and mixes a received signal with a local signal that is part of the transmitted signal to produce a beat signal consisting of a fundamental frequency component as a function of the distance to and relative speed of a target object. The radar apparatus also includes an amplitude modulator which modulates the amplitude of at least one of the transmitted signal, the received signal, and the local signal in accordance with the modulating signal so that the modulation index falls within a range of zero (0) to one (1). This allows harmonic components with an improved SN ratio to be extracted from the beat signal which may be used in calculating the fundamental frequency component of the beat signal.

Abstract: A modulation signal generating section produces a modulation signal for controlling an oscillation frequency of a voltage-controlled oscillator. The modulation signal generating section comprises a triangular wave oscillator producing a linear modulation component of a triangular waveform which varies the modulation frequency linearly, a sine wave oscillator producing a cyclic modulation component of a sine waveform which varies the modulation frequency cyclically, and a signal adder producing the modulation signal by adding the linear modulation component and the cyclic modulation component. A transmitting signal frequency modulated by the modulation signal is mixed with a received signal and produces a beat signal comprising a fundamental wave component of a beat frequency and harmonic components.

Abstract: In a Frequency Modulated Continuous Wave (FMCW) radar, a radar return signal is mixed with a delayed frequency sweep waveform to gain a ranging signal to noise ratio (RSNR) higher than the RSNR available from mixing the return signal with a transmitted waveform.

Abstract: A modular radar system using both FM/CW and pulse waveforms for automotive collision avoidance applications.

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: The wave is modulated in frequency (or in phase) and a measurement is made of the frequency of the beat between the transmitted wave and the received wave which gives the propagation delay and hence the distance. The method provides for the superimposing, on this modulation, of a periodic over-modulation with a period that is equal to or is a multiple of the propagation delay corresponding to a pre-selected expected distance. The device comprises, at transmission, in the case of a linear modulation of frequency, a saw-tooth generator (31) and a generator of over-modulations (32), for example sinusoidal, controlled by the expected distance given by a distance selector (30). The modulation signal of the transmitter is obtained by summation (33) of the signals of the two generators (31, 32).

Abstract: A road vehicle radar system for discriminating between hazard and non-hazard targets within a predetermined zone uses a pair of frequency modulated continuous wave radar cycles (FM-CW) and a single continuous wave cycle (CW) in the generation of radar quantities for measuring target range and apparent target velocity. Measured quantities from the FM-CW and CW cycles are compared with predetermined quantities for discriminating between hazard and non-hazard targets.

Abstract: Scaled multiple function non-linear FM waveforms are generated for use in digitally implemented low frequency radar. The non-linear FM waveforms are generated by combining a plurality of functions, each having varying characteristics, to form a single waveform which has the desirable characteristics of weighted linear FM waveforms without the undesirable attributes due to weighting. Accordingly, the use of the non-linear FM waveform results in an increase in detection range of eight percent over existing linear FM waveforms with no degradation in range resolution.

Abstract: The invention provides a method of determining the range of a radar signal reflecting object by utilizing a radar frequency carrier wave modulated by a first short code having a first repetition rate and a second code having a bit rate equal to the first code repetition rate. A received echo is first passed to an analogue correlator for correlation against a delayed version of the first code, and the output of the analogue correlator is fed to a digital correlator for correlation therein against the second code. In this way, the high bandwidth (greater range resolution) of analogue correlation can be combined with the lower bandwidth (longer ambiguity function) of digital correlation to provide high resolution target detection without ambiguity and at a fast rate without the need for a very large number of correlators.

Abstract: An FM/CW radar system is disclosed for determining a safe stopping distance between a moving vehicle and a potential obstacle. The radar signal is modulated linearly over several slopes. A microstrip phased array transmit/receive antenna is also disclosed having a hybrid tap, corporate feed structure. Signals from the antenna are amplified and filtered, and passed through an analog to digital converter to a signal processor, which performs a Fast Fourier Transform on the signals to convert them from time domain data to frequency domain data. The frequency domain data is then used to solve target range and doppler equations, determine safe stopping distances, and sound or display alarms if the safe stopping distance has been violated. A sensitivity control adjusts for road conditions or operator reaction time variations.

Abstract: A continuous-wave radar set is additionally usable as a transmitter for transmitting messages, e.g., voice, data, or control information. Besides a first modulator (SM) which produces a sawtooth or triangular frequency modulation of the radar RF signal, there is an additional modulator (ZM) which modulates the radar RF signal with a useful signal during the flyback, i.e., in a phase in which the signal is not used for radar purposes. To achieve exact synchronization between the two modulators, both modulators are controlled by the same clock generator (T).