Abstract: A radar system achieves adjustment of a time-change characteristic of a frequency-modulating voltage signal to a voltage-controlled oscillator for determining a transmitting signal such that the time-change characteristic of the frequency-modulating voltage signal is changed by a minute amount and the frequency spectrum of a beat signal is determined. The adjustment is performed so that the shape of a bulge in signal intensity included in the frequency spectrum is the sharpest.

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 radar signal processing apparatus has a range gate for extracting range gate data sequences from a memory, a first frequency extraction section which extracts a beat frequency corresponding to a target by performing frequency analysis by FFT at a low computation load and with low frequency measurement accuracy on all range gate data sequences extracted by the range gate, a second frequency extraction section which extracts a beat frequency corresponding to the target by performing frequency analysis by FFT at a high computation load and with high frequency measurement accuracy only on the range gate data sequence from which a beat frequency has been extracted by the first frequency extraction section, and a distance and speed derivation section which obtains the relative distance and the relative speed of the target on the basis of the beat frequency extracted by the second frequency extraction section.

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: A radar system is capable of transmitting necessary information through a very small amount of data from a radar device to a host device via a bus with a limited bandwidth. A radar sensor generates a beat signal between a transmission signal and a reflected signal from a target. A signal processor determines a spectrum of the beat signal and compresses the data indicating the spectrum. The resultant compressed data is transmitted to the host device via a bus. The host device decompresses the received data thereby reproducing the spectrum data. The host device then detects the target on the basis of the reproduced spectrum data.

Abstract: A radar system includes a transmitting/receiving unit, having a voltage controlled oscillator, for repeatedly transmitting a triangular transmission signal including a frequency-gradually-rising up-modulation interval and a frequency-gradually-dropping down-modulation interval and for receiving a reception signal including a reflected signal from a target, a frequency analysis unit, a data storing unit for storing time-varying characteristics of input values to a D/A converter that monotonically change an oscillation frequency of the voltage controlled oscillator with time, in the form of data concerning an expression representing the time-varying characteristics, and a data processing unit for determining the input values to the D/A converter with reference to the data. At least one of the relative distance to the target and the relative speed of the target is detected based on a beat signal during the up-modulation interval and the beat signal during the down-modulation interval.

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 radar device precisely detects a target in short time intervals by detecting a true peak frequency with high accuracy via a calculation which does not require a large amount of computation. A discrete frequency spectrum of a beat signal multiplied by a window function is determined, and values of signal strength at two discrete frequencies which are, respectively, higher and lower than a peak frequency of the discrete frequency spectrum of the beat signal and which are adjacent to the peak frequency. The frequency difference between the discrete peak frequency of the beat signal and the peak frequency of the window function is then determined from the ratio between the values of signal strength at those two discrete frequencies adjacent to the peak frequency. Thus, the true peak frequency of the beat signal is determined with a high frequency resolution.

Abstract: A distance and speed measuring method and a radar signal processing apparatus using the method are provided which are capable of obtaining highly reliable measurement results while reducing the number of false targets and undetectable targets, by obtaining the relative distance and the relative speed of each target based on the frequencies of a beat signal of up (or down) phase alone through the use of information in a time series direction of the frequencies of the beat signal of up (or down) phase.

Abstract: A radar performs accurate and appropriate pairing even if peaks of approximately identical signal intensities or even if a plurality of peak groups having identical representative beam bearings exist in the frequency spectrum. First, the peak frequency of a peak which appears in the frequency spectrum is determined for each of an up-modulating interval and a down-modulating interval in predetermined beam bearings, and signal-intensity profiles in the beam bearings are extracted with regard to a plurality of beam portions which are adjacent to the beam bearings. Next, the correlation level between the signal-intensity profiles at the up-modulating interval and the down-modulating interval is determined, and pairing is performed in sequence starting from the profiles having a higher correlation level.

Abstract: A sensor front end is disclosed that is able to discriminate objects based on their range from the sensor. The sensor includes an antenna that transmits a sensor signal and, if an object is present receives a reflected signal therefrom. A pulsed oscillator provides a pulsed first signal having a first frequency and phase, and wherein the pulsed oscillator provides the pulsed first signal for a predetermined pulse duration and with a predetermined pulse repetition frequency. The pulsed oscillator provides the pulsed first signal to a first input port of a dual mode mixer that is further coupled to the antenna via a second port. The dual mode mixer transmits a portion of the pulsed first signal from the first input port to the second port and thus to the antenna to be transmitted as the sensor signal. In addition, the dual mode mixer uses a portion of the first signal to mix with the received reflected signal. The dual mode mixer then provides a mixed signal as an output at a third port.

Abstract: The invention detects a ghost occurring due to mispairing, reflections from a wall, or the like, and improves the ability of a radar to track targets when actual relative velocity changes by more than a certain value. If a stationary target is present within a prescribed region centered about a moving target, the stationary target is excluded from output data by determining it as being a target resulting from mispairing due to the detection of guardrail posts or similar structures. Further, a moving target that is expected to collide with an eligible target is also excluded from the output data by determining it as being a target resulting from mispairing due to the detection of a target having many reflecting points. For a moving target showing an unlikely relative velocity, pairing with some other peak is attempted by determining the moving target as being a target resulting from mispairing due to the detection of a plurality of moving targets moving in the same direction.

Abstract: When a new target is detected, if it is determined that the distance difference between the newly detected target and the previously detected target is within a predetermined range, the difference between the relative velocity of the newly detected target and the relative velocity of the previously detected target is obtained to determine whether the difference is greater than a predetermined value &Dgr;Va, and when the difference is greater than the predetermined value, it is determined that the new target is a target obtained as a result of mispairing.

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: 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: In an FM-CW radar system, regarding peaks appearing in the frequency spectrum of a beat signal in an FM-CW radar, groups of consecutive peaks in beam bearings within a predetermined frequency difference are regarded as being caused by reflected waves from a single target, and based on a combination of a peak group in an up-modulating interval and a peak group in a down-modulating interval, a relative distance to a target and its relative speed are determined.

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: A system 100 is disclosed for monitoring the position of one or more RFID tags 201. The system has a detector 301 incorporating circuitry 304 for detecting changes in the range of an RFID tag 201 from the detector and for triggering an alarm 401 if a detected change in range of an RFID tag 201 exceeds a predetermined threshold or if the RFID radio tag cannot be detected by the detector 301. Range may be detected, for example, by measuring the time of a returned radio signal from a tag 201, by measuring the strength of a returned radio signal from a tag, or by detecting changes in a periodic interval at which energy is transmitted by a tag.

Abstract: A device for non-contractual measurement of the speed of an object moving over a surface comprises a means for radiating a signal of fixed frequency at an angle onto the surface in or against the direction of motion, said angle being variable by the movement of the object, and for receiving a Doppler-shifted signal reflected at the surface. A means is provided for combining a plurality of reflected Doppler-shifted signals, which are received in temporal succession, so as to produce a combined spectrum. The device for non-contractual speed measurement additionally comprises a means for detecting from the combined spectrum the spectral portion having the highest or lowest frequency and exceeding a predetermined signal power, and a means for deducing the speed from the frequency of the detected spectral portion.

Abstract: A sensor front end for an electronic radar sensor is disclosed that provides for a lower parts count while providing technical functionality by using multifunction parts, i.e., parts that are used both in transmitting and receiving. The sensor front end includes a continuous wave signal source that functions as a signal source when the front end is transmitting a signal and as a local oscillator when the front end is receiving a signal. The sensor front end also includes a tri-mode mixer that functions as a phase-modulator and transmit switch when the front end is transmitting a signal and as a mixer/down-converter when the front end is receiving a signal. The sensor front end further includes a common aperture antenna that acts as both a transmitting antenna for transmitting a sensor signal and for receiving a reflected signal from a object.

Abstract: A device for measuring the speed reached and the distance covered by a moving user or object has a Doppler radar sensor that may be secured to the moving user or object and is made of a microwave strip transmission line sensor (1) that generates measurement signals and supplies them to an evaluation unit (2) with a sender that transmits the evaluated data to a separate processing and display unit (8).

Abstract: In order to occur a collision warning to prevent the collision in accurate by detecting the preceding vehicle or target, a vehicle lane position estimation device comprising a means for measuring a distance between said host vehicle and said preceding vehicle or a oncoming vehicle, a direction angle from said host vehicle, an angular velocity and a velocity of said host vehicle, a means for calculating lateral and longitudinal distance between said host vehicle and said preceding vehicle or said oncoming vehicle, a means for capturing a front stationary object, a means for obtaining movement of the preceding vehicle or position of the oncoming vehicle, and a means to estimate a lane position of said front stationary object from a relationship of the stationary object being captured and the preceding vehicle being obtained and a positional relationship with the oncoming vehicle.

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 scan type radar device capable of detecting a lateral position of a target even if a peak showing the lateral position of the target irregularly fluctuates in the lateral direction as well as reducing the mis-pairing. The former is achievable by changing a reference value of the lateral fluctuation of the target when all the past and present target data fluctuate to an extent exceeding the reference value. The latter is achievable by forecasting a representative peak position at this time in both of up-beat and down-beat from the peak position data at the preceding time and carrying out the past-correspondence grouping of the up-beat and the down-beat at this time in the vicinity of the position of the representative peak forecast this time; the pairing being carried out by using the representative peak calculated by the past-correspondence grouping.

Abstract: A method capable of determining whether a target detected by a radar is a stationary on-road object or not is disclosed, wherein a fluctuation in the reception level of a reflected wave from a target is obtained in relation to the distance of the target, a difference in reception level between a maximum point and a minimum point is obtained from the fluctuation of the reception level, and when the obtained difference is larger than a predetermined threshold value, it is determined that the target is a stationary on-road object. Further, slope over the distance between the maximum point and the minimum point is obtained, and when the obtained slope is greater than a predetermined threshold value, it is determined that the target is a stationary on-road object. Further, the distance between maximum points or between minimum points is obtained, and when the obtained distance is smaller than a predetermined threshold value, it is determined that the target is a stationary on-road object.

Abstract: An FMCW radar is provided which may be employed in automotive anti-collision or radar cruise control systems. In a distance measuring mode, only one of channels is used to sample a beat signal continuously, thereby allowing a sampling frequency to be increased up to Nc times that in an azimuth measuring mode and a sweep time in which a transmit signal sweeps in frequency upward and downward cyclically to be minimized. This causes half the sampling frequency to be higher than a frequency component arising sufficiently from a distant target present outside a preset radar range, thereby eliminating an error in detecting the distant target as being located inside the preset radar range.

Abstract: An FM-CW radar system comprises a modulating signal generating means for changing a modulating signal to be applied to a FM-CW wave, a calculating means for calculating a distance or relative velocity with respect to a target object by performing processing for detection by fast-Fourier transforming a beat signal occurring between a transmitted signal and a received signal, and a control means for determining a detection range based on the calculated distance, and for performing control to change the modulating signal, wherein the modulating signal is changed by changing one parameter selected from among a modulation frequency, a triangular wave frequency, and a transmit wave center frequency. The detection range is set to a distance obtained by adding a prescribed distance to the shortest distance detected, or to a distance obtained by subtracting a prescribed distance from the distance of a fixed object.

Abstract: The occurrence of an axis displacement in a horizontal direction in a vehicle-to-vehicle distance controlling radar is detected, the amount of the axis displacement is determined, and an azimuth angle is corrected using the thus determined amount of the axis displacement. The frequency with which vehicle-to-vehicle distance control is released or re-set is measured and, if the frequency is higher than a threshold, it is determined that the axis is displaced. The amount of the axis displacement is determined from the angle of the locus of a stationary target. The azimuth angle of the target is corrected using the thus determined axis displacement angle.

Abstract: An apparatus for storing data of a device, in particular of a motor vehicle, which is to be monitored, in which apparatus the data are preferably stored by means of a control unit in a memory unit. In an apparatus which permits a plurality of data which change continuously during the service life of the motor vehicle to be stored in an operationally reliable way and with a high processing speed, the fixed data and the continuously updated data of the apparatus which is to be monitored are stored in the memory unit 15 which contains the open-loop and/or closed-loop control processes.

Abstract: A modulation signal generation circuit performs frequency modulation of a VCO with a triangular wave for operation as an FM-CW radar. A signal processing circuit gives a modulation signal for detection generated from the modulation signal generation circuit to the VCO. A high-frequency signal subjected to frequency modulation in the VCO is transmitted as a radio wave from a transmission antenna and is reflected on a target and the reflected radio wave is received at a reception antenna. The reception signal and the high-frequency signal are mixed by a mixer to provide a beat signal and frequency shift corresponding to a voltage V1 is detected from the frequency of the beat signal. If the voltage V1 of the modulation signal for detection is switched, the frequency shift corresponding to different voltage V1 can be provided and the frequency modulation characteristic can be detected.

Abstract: A radar system includes a detection-control circuit for transmitting and receiving the beam of a millimeter-wave signal for detecting a relative position and a relative speed to a target, and a scanning unit for scanning the direction of the beam over a predetermined range. The state of the scanning unit can be switched between a resting state wherein scanning is stopped and the beam is directed towards the center of the scanning range while the detection-control circuit continues detection control, and a scanning state wherein the direction of the beam is scanned over a predetermined range.

Abstract: A device and process for measuring distances and/or speeds between a motor vehicle and several objects, like mobile targets and fixed targets, has an FMCW radar system, where the motor vehicle transmits a signal, whose transmitting frequency is modulated with at least two frequency ramps. A device detects the receiving signals from the objects and determines the respective straight lines and the intersecting points of these straight lines in a speed-distance diagram. A sorting device sorts out the intersecting points from fixed targets and the related straight lines. A device outputs the distances and/or the speeds, which correspond to the other intersecting points.

Abstract: A radar signal processing apparatus has a range gate for extracting range gate data sequences from a memory, a first frequency extraction section which extracts a beat frequency corresponding to a target by performing frequency analysis by FFT at a low computation load and with low frequency measurement accuracy on all range gate data sequences extracted by the range gate, a second frequency extraction section which extracts a beat frequency corresponding to the target by performing frequency analysis by FFT at a high computation load and with high frequency measurement accuracy only on the range gate data sequence from which a beat frequency has been extracted by the first frequency extraction section, and a distance and speed derivation section which obtains the relative distance and the relative speed of the target on the basis of the beat frequency extracted by the second frequency extraction section.

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 transmitted signal and a received signal are combined and the combination is expected to determine whether or not a target signal is present. Either the transmitted signal or the received signal is combined with an auxiliary signal containing a range of frequencies corresponding to an anticipated Doppler shift, so that an output of the combined transmitted and received signal will be present only if a target signal exhibiting a Doppler shift within the anticipated range is present. The auxiliary signal preferably comprises finite-duration signal portions of different types so as to provide a substantially uniform frequency response throughout the selected range.

Abstract: In an FM-CW radar system, a frequency modulating wave output from said modulating signal generator has a frequency variation skew with respect to a time axis (modulation skew), and the radar system includes a means for varying the modulation skew by controlling the modulation frequency amplitude or modulation period of the modulating signal. The radar system further includes a means for discriminating a signal component varying in response to the variation of the modulation skew, thereby discriminating a signal related to a target object from other signals. In the case of an FM-CW radar system that performs transmission and/or reception by time division ON-OFF control, the radar system includes a means for discriminating a signal which, when the frequency used to perform the ON-OFF control is varied, varies in response to the variation of the frequency, thereby discriminating a signal related to a target object from other signals.

Abstract: In a radar, a coupler extracts a part of a transmission signal as a local signal and a mixer mixes a reception signal from a circulator and the local signal so as to output an intermediate frequency signal which is the frequency difference between the transmission signal and the reception signal. An IF-amplifying circuit amplifies the intermediate frequency signal and an AD converter converts the signal to digital data. A DC-removing unit removes a DC component by subtracting the average from the data and an FFT operation unit performs fast Fourier transform so that the distance to a target and the relative velocity of the target are calculated based on a peak included in the frequency spectrum.

Abstract: A system for sensing and measuring the relative motion of an object, comprising a transceiver device configured to transmit a signal toward an object, a plurality of detectors offset in phase to receive the transmitted signal and a reflected signal, and a processor configured with logic to measure a phase shift resulting from the relative motion of the object between the transmitted signal and the reflected signal at the plurality of detectors, wherein the processor is further configured with the logic to relate the phase shift to the relative motion of the object.

Abstract: A method and apparatus for measuring the parameters of atmospheric turbulent flows utilizes the Doppler shifted frequencies of received radar signals backscattered from sound generated aerodynamically by atmospheric turbulent flows. Doppler frequency bandwidths of the received backscattered signals are used to estimate the atmospheric flow turbulence and the mean frequency within a bandwidth is processed to estimate its radial flow velocity. Total flow velocity and the flow velocity angle with respect to the antenna boresight of the atmospheric turbulent flow may be estimated by estimating the radial flow velocity at two radial positions and processing these radial velocities. Processing of the Doppler data is initiated when the total signal power within the Doppler frequency band exceeds a predetermined power level.

Abstract: A continuous signal of a radio frequency source is connected to an antenna using at least one mixer to generate and analyze radar pulses. To generate a radar pulse, the at least one mixer is briefly placed into a state of low throughput loss. After the radar pulse is generated and transmitted, the at least one mixer is switched over to a receive mode to analyze a mixed signal formed by a receive signal, in particular at least one radar pulse reflected by an object, and the continuous signal of the radio frequency source.

Abstract: A method is described for detecting moving and/or stationary objects in the path of a vehicle, where the distance and velocity of the reflecting object are determined by using a radar sensor, where the frequency of the signal transmitted is modulated in the shape of a ramp according to a multi-ramp method, and some ramps have a lower slope in the frequency curve. The higher spectral components of the mixed signals from the ramps having the lower slope, which are to be assigned to a distance range of the reflecting object which is greater than the distance range belonging to the ramps having the greater slope, are used to determine the distance, speed and angle of objects.

Abstract: A radar device in which a much more precise demodulation can be made with an inexpensive circuit, free of the output variation of the frequency-modulated transmission signal. The radar device includes an oscillator which produces and outputs a frequency-modulated electromagnetic wave to a switching circuit by way of a directional coupler. The switching circuit uses switching modulation to radiate the electromagnetic wave from a transmitting antenna. The radiated electromagnetic wave after being reflected from an obstacle is received at a reception antenna. A mixer mixes this reception signal and a local signal fed from the directional coupler to produce a mixing signal which is to be fed to a high pass filter. The high pass filter deletes a low frequency output variation noise which is contained in the mixing signal and which occurs in the frequency modulation in the oscillator. The resulting mixing signal is, with the noise deleted, fed by way of an AC amplifier, to a switching demodulating circuit.

Abstract: A radar signal processing method and system for detecting target objects of unknown acceleration and having low SNRs which reduces the computational burdens and provides a more efficient way of performing the operation of non-coherent integration. Radar signal processing is conducted according to a predetermined scheme in which partially processed received signal data is selectively stored and reused, reducing redundant processing. The radar system receives return signals frequency shifted from a predetermined frequency scheme by unknown amounts. The received signals are coherently integrated transforming them into frequency domain templates which are non-coherently arranged into an array matrix. The data of the frequency domain templates are processed to form presums which are stored for use in forming higher level presums and for forming acceleration bins. Once the acceleration bins have been formed, they are analyzed to detect the presence of target object return signals.

Abstract: A system for sensing and measuring the relative motion of an object, comprising a transceiver device configured to transmit a signal toward an object, a plurality of detectors offset in phase to receive the transmitted signal and a reflected signal, and a processor configured with logic to measure a phase shift resulting from the relative motion of the object between the transmitted signal and the reflected signal at the plurality of detectors, wherein the processor is further configured with the logic to relate the phase shift to the relative motion of the object.

Abstract: A radar apparatus mounted on a vehicle includes a detecting section and a fault determining section. The detecting section includes a radar unit and detects a detection object using radar wave radiated from a radar unit toward the detection object and reflected radar wave from the detection target to the radar unit. The fault determining section determines whether any fault has occurred in the radar unit, based on the detecting result of the detection object and a movement distance of the vehicle, and generates a fault detection signal, when it is determined that any fault has occurred in the radar unit.

Abstract: A compact millimeter wave radar transceiver at low cost is provided wherein a direct current voltage applying circuit is coupled to a high frequency line to apply a fast pulse wave without losing a sharp input pulse pattern. A voltage is applied to a negative resistance diode, such as a Gunn diode, which is variably controlled to vary the diode oscillating frequency signal, which signal is outputted as a transmitting wave. The transmitted wave is reflected by a target and received by the negative resistance diode. The received wave is detected as a heterodyne detection utilizing a non-linear property of the negative resistance diode. A frequency difference between the transmitted wave and the received reflected wave is outputted via a low-pass filter and processed to detect the target.

Abstract: A radar sensor device for detecting the distance and/or the speed of an object relative to the sensor device is provided with an oscillator, which can be frequency detuned through the use of a modulation function. The radar sensor device has a power switch, which can be driven by a power control function, for varying the transmitter power. The sensor device is to be operated in an alternating fashion, through the use of a variable setting of the modulation and power control functions, in at least two different, mutually overlapping operating modes which are tuned to different measuring ranges of the sensor device.

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: An outdoor microwave transceiver intrusion detector that alternately transmits pulses of RF energy at two different frequencies and uses range and direction of travel information derived from the phase of the two Doppler responses to optimize the signal processing and apply range dependent thresholds. The time delay between the onset of the transmitted pulse and the sample of the Doppler response is controlled to provide an accurate range cutoff. The two frequencies are selected so that the difference in phase of the Doppler response at the two frequencies increases from zero to ninety degrees as the target goes from the Transceiver to the maximum range. Digital signal processing is used to measure the difference in phase of the two Doppler responses and translate this information into location of the target. The location information is used to create a number of range bins.

Abstract: AN FM pulse Doppler radar apparatus performs pulse modulation of modulating waves having repeatedly increasing and decreasing frequency, transmits thus modulated waves, receives at each range gate having an interval equivalent to a pulse width, reflected waves reflected from an object, determines a distance according to the range gate, and calculates the distance to the object and the relative velocity of the object based on the difference between frequencies of the transmission waves and the received waves. The apparatus includes a velocity determining unit for determining velocity of the radar-mounted vehicle and a comparison-and-detection unit for comparing the detected distance according to the range gate and the distance calculated based on the difference between the frequencies of the transmission waves and the received waves.