Abstract: An operation mode control method implemented by a radar system, the operation mode control method includes steps of: (S1) receiving a single target tracking (STT) triggering data comprising a representation of triggering of a STT tracking mode and a selected tracking target to be tracked by the radar system; (S2) controlling a radar sensor to emit detection wave beam; (S3) controlling, the radar sensor to receive echo waves; (S4) analyzing, echo signal to generate STT target data; (S5) executing a STT program to obtain a tracking data of a selected tracking target; (S6) outputting the tracking data to a memory device for storage or to a human-machine interface (HMI) device for presenting to the user of the radar system.

Abstract: A vehicle-based method of determining the extent to which a target object is a single scatterer, said vehicle including a radar system including a radar transmit element, adapted to send a radar signal towards said target object, and an antenna receive array comprising a plurality M of a receive elements, providing a corresponding plurality of N radar receive channels, and adapted to receive radar signals reflected from said target object, said method comprising: a) transmitting a radar signal from said radar transmit element to said target object; b) receiving the reflected signal of the signal transmitted in step a) from the target object at said plurality of receiver elements; c) for each antenna element or channel, processing the received signal to provide amplitude or power data in the frequency domain; d) with respect to the data in step c), for each receive element/channel, determining the frequency with the maximum amplitude or power; e) determining the degree of variability of the results of step d)

Abstract: A mainlobe detection process can include a number of tests that are performed to define when the monopulse antenna system will transition from open loop scanning to closed loop scanning and then to tracking. A hybrid tracking technique is also provided which adaptively discovers and corrects for phase alignment error. Magnitude-only tracking can be performed initially to locate the nulls in the azimuth and elevation ratios and to identify the magnitudes of these ratios at these nulls. Phase tracking can be then performed. During phase tracking, phase corrections can be repeatedly applied to the azimuth and elevation difference channels to correct any phase error that may exist. During this process, the magnitudes of the ratios can be used to determine how the phase corrections should be adjusted. Once the hybrid tracking process is complete, the monopulse antenna system is properly phase-aligned and phase tracking will be correctly employed.

Abstract: Disclosed is an antenna device in which an excitation phase changing unit (4) for changing the excitation phases of element antennas (2-1n) to (2-8n) by controlling phase shifters (3-1n) to (3-8n) dependently on preset phase values is disposed, and every time the excitation phases are changed by the excitation phase changing unit (4), a radiation pattern forming unit (12) shifts the phases of a sum signal and a difference signal, and forms a monopulse sum pattern by time-integrating the sum signal after phase shift and also forms a monopulse difference pattern by time-integrating the difference signal after phase shift.

Abstract: System and apparatus embodiments are provided for beam-steering. In an embodiment, an apparatus includes a first hybrid splitter/combiner connected to a 0-th phase-mode feed of an array of antenna elements, a second hybrid splitter/combiner, a first pair of variable phase shifters connecting the first hybrid splitter/combiner to the second hybrid splitter/combiner, wherein the first pair of variable phase shifters control a steering direction of a main output beam radial with respect to an array axis by adjustments of respective phases of the variable phase shifters, and wherein the array axis is perpendicular to a plane of the array, and a third variable phase shifter connecting a 1-st phase-mode feed of an array of elements to an input of the first hybrid splitter/combiner, wherein the third variable phase shifter is configured to independently control a direction of the main output beam in a direction circumferential with respect to the array axis.

Abstract: A sub-carrier successive approximation (SCSA) radar having a sufficiently high accuracy to capture 3D images of concealed objects. The invention is phase-based, and directly measures round trip time by estimating the phase delay of the carrier. One of its advantages is that the carrier does not need to sweep across a wide frequency range, thereby relaxing RF front-end bandwidth and linearity requirements. SCSA radar accuracy is limited only by the extent of system noise, allowing very high accuracy to be achieved with a sufficient integration period. The SCSA radar can be readily implemented in CMOS, as well as other device technologies, and fabricated within one or more small integrated circuits.

Abstract: A method for direction finding by means of monopulse formation in a radar system with electronically controlled group antenna and analog beam shaping of sum and difference channels, a self-test of the antenna being carried out to identify failed receiving elements, and the result of the self-test going directly into the monopulse formation and the test thereby being error corrected. The result of the self-test is converted into correction values that, independently of the antenna viewing direction, are combined with those from the sum channel signal and the difference channel signals of the antenna.

Abstract: A method and apparatus for identifying locations of objects. A portion of a sum signal corresponding to angular locations and velocities with respect to a sensor system that are different from a selected angular location and a selected velocity with respect to the sensor system, respectively, is modified to form a set of modified sum signals. A portion of a difference signal corresponding to the angular locations and the velocities with respect to the sensor system that are different from the selected angular location and the selected velocity with respect to the sensor system, respectively, is modified to form a modified difference signal. An angular location of a target object is identified with respect to the sensor system using the set of modified sum signals and the modified difference signal.

Abstract: A method and apparatus for processing electromagnetic waves. Electromagnetic waves are transmitted in a selected direction toward a target object from a first array of antenna elements. Scattered electromagnetic waves generated from the electromagnetic waves are received at a first portion of a second array of antenna elements configured to receive the scattered electromagnetic waves in a first direction with respect to the selected direction and at a second portion of the second array of antenna elements configured to receive the scattered electromagnetic waves in a second direction with respect to the selected direction. First information in the scattered electromagnetic waves received by the first portion is subtracted from second information in the scattered electromagnetic waves received by the second portion to form difference data. An elevation angle is identified between a direction of the target object and the selected direction using the difference data.

Abstract: In accordance with one of embodiments of the present invention, a frequency resolution processing unit calculates complex number data based on a beat signal caused by a receiving wave coming from a target and a transmission wave. A target detection unit detects a peak value from the intensities of beat frequencies, and then detects an existence of the target. The target link unit makes association between a target detected in the present detecting cycle and the target detected in the past detecting cycle. A direction estimating unit generates a generative complex number data based on the complex number data so as to correspond to a data generation unit. The direction estimating unit calculates, for each antenna, an incoming direction of the receiving wave based on each of normal equations formed by use of the complex number data of the beat frequency which an existence of the target is detected and the generative complex number data.

Abstract: A radar-based physiological motion sensor is disclosed. Doppler-shifted signals can be extracted from the signals received by the sensor. The Doppler-shifted signals can be digitized and processed subsequently to extract information related to the cardiopulmonary motion in one or more subjects. The information can include respiratory rates, heart rates, waveforms due to respiratory and cardiac activity, direction of arrival, abnormal or paradoxical breathing, etc. In various embodiments, the extracted information can be displayed on a display.

Abstract: A radar receiver has plural antenna system processors each for performing coherent integration on the basis of correlation values between a reception signal and a transmission signal using correction amounts for phase variations corresponding to plural Doppler frequencies, plural correlation matrix generators for generating, for each of the plural different Doppler frequencies, correlation matrices which are pieces of phase difference information relating to an arrangement of reception antennas on the basis of sets of outputs of the coherent integration, respectively, an adder for adding together outputs of the plural correlation matrix generators, and an incoming direction estimator for estimating an incoming direction of reflection waves on the basis of outputs of the adder.

Abstract: A method and system for locating a target, of azimuth Aestimatedtarget and of elevation angle Sestimatedtarget, in space by a carrier uses at least one first antenna array with electronic scanning ARRAY_H and at least one second antenna array with electronic scanning ARRAY_B. The target emits a signal in response to an interrogation from the carrier, each of said antenna arrays includes at least one antenna and the total number of antennas used is at least equal to three.

Abstract: An evaluation method, e.g., for a driver assistance system of a motor vehicle, is provided for object detection using a radar sensor, which synchronously emits at least two separate radar beam lobes, that cover an angular range to be scanned, and which receives respective target responses as measured values. At least two target responses of the at least two separate radar beam lobes of the radar sensor are arithmetically superposed in such a way that a synthetic radar beam lobe is created having at least one predetermined zero value in the scanned angular range.

Abstract: A radio detection device includes two or more reception antennas, for detecting a detecting object by a mono-pulse method; the radio detection device including: a variable gain unit for discretely changing respective signal intensity of a difference signal and a sum signal of each reception signal received by the two or more reception antennas; an A/D conversion unit for performing A/D conversion process on the difference signal or the sum signal, the difference signal or the sum signal having the signal intensity changed by the variable gain unit; an angle calculating portion for calculating an angle by the mono-pulse method using the difference signal and the sum signal after the A/D conversion process by the A/D conversion unit; and a control unit for performing a control of individually switching a conversion magnification of the signal intensity by the variable gain unit with respect to the difference signal and the sum signal.

Abstract: A method for determining target angles based on data received from a monopulse radar array antenna includes receiving from a beamformer that generates beams from signals generated by the monopulse radar antenna signals having data indicative of a sum beam, an azimuth difference beam, an elevation difference beam, and a delta-delta beam; based on the received signals, determining by the processor an azimuth monopulse ratio, an elevation monopulse ratio, a first complementary monopulse ratio based on the ratio of the delta-delta beam to the delta elevation beam, and a second complementary monopulse ratio based on the ratio of the delta-delta beam to the delta azimuth beam; determining an azimuth angle by the processor based on the azimuth monopulse ratio and the first complementary monopulse ratio; determining an elevation angle by the processor based on the elevation monopulse ratio and the second complementary monopulse ratio; providing an output signal indicative of the azimuth angle; and providing an output

Abstract: A moving object detection apparatus comprises a transmitter, a receiver, a detection portion, a binary conversion portion and a judgment portion. The transmitter emits energy waves with a first frequency to a detection area. When receiving incoming energy waves from the detection area, the receiver generates an electric signal corresponding to the incoming energy waves. The detection portion obtains a detection signal from a reference signal with the first frequency and the electric signal. The binary conversion portion compares the detection signal with a conversion threshold signal to obtain a binary signal. The judgment portion judges whether or not a moving object approaching or leaving the receiver exists in the detection area based on the binary signal.

Abstract: A proposed spread spectrum signal receiver includes a radio front-end unit and a processing unit. The radio front-end unit, in turn, has an antenna, a digitizing circuit and a primary buffer unit. The antenna is adapted to receive radio signals (SHF) from a plurality of signal sources, and the digitizing circuit is adapted to downconvert and filter the received signals (SHF), and generate sample values (SBP-D) thereof. The primary buffer unit is adapted to temporarily store the sample values (SBP-D) from the digitizing circuit and allow the processing unit to read out a first set of stored sample values (SBP-D) contemporaneously with the storing of a second set of sample values (SBP-D) in the primary buffer unit. The processing unit is adapted to receive the sample values (SBP-D) from the primary buffer unit, and based thereon, produce position/time related data (DPT).

Abstract: A method for target detection and angle estimation in a radar system includes receiving a signal from a radar array; based on the received signal, performing monopulse beamforming to obtain one or more monopulse beams; based on the monopulse beams, determining monopulse ratios; using maximum likelihood estimation based on the determined monopulse ratios to determine a monopulse ratio estimate corresponding to a maximum of a likelihood function; accessing a table correlating monopulse ratio estimates and target angle values and determining from the table an estimated target angle; accessing a complex target amplitude corresponding to the estimated target angle, comparing the complex target amplitude to a threshold; and if, based on the step of comparing, the target amplitude exceeds the threshold, providing an output signal indicative of target detection and the estimated target angle.

Abstract: Systems and methods are provided for determining first and second azimuth angle values representing two closely spaced targets. Monopulse radar scan data is produced and processed to provide quadrature angle data, merged azimuth angle data, and a maximum magnitude of the quadrature angle. A quadrature angle methodology that derives the first and second azimuth angle values from an integration of the quadrature angle data over an angular region within the monopulse scan is applied if the maximum quadrature angle magnitude exceeds the threshold value. A merged azimuth angle methodology that fits the merged azimuth angle data to a polynomial as a function of a boresight angle of the monopulse radar to derive the first and second azimuth angle values is applied if the maximum quadrature angle magnitude does not exceed the threshold value. The first and second azimuth angle values are then displayed to a user.

Abstract: A surface acoustic wave (SAW) expander based transmitter and correlator based receiver comprises SAW devices that perform expander or correlator functions based on the types of signals inputted to the SAW devices. The SAW devices incorporate chirp with adaptive interference and programmable coding capabilities. The SAW devices and method of operating the devices allow the implementation of very low power radios that overcome problems with temperature drift, lithography constraints and interference and jamming suffered by prior art implementations.

Abstract: Disclosed is a spread spectrum clock generator which includes: a first delay control type oscillator that variably controls an oscillation period at a control period interval according to a control signal; a control circuit; a maximum modulation value determination circuit that determines a maximum modulation value from a predetermined value, a frequency control signal, and a given modulation degree setting signal; a modulation signal generation circuit that receives the maximum modulation value from the maximum modulation value determination circuit and generates a modulation control signal within the maximum modulation value; and a second delay control type oscillator that receives a value obtained by adding the modulation control signal from the modulation signal generation circuit to the frequency control signal as a control signal and variably controls the oscillation period of an output clock signal at the control period interval according to the control signal.

Abstract: Channel quality can be detected accurately in a wireless transmission system such as an HSDPA method. In the case of estimating a channel quality of a signal transmitted by a Code Division Multiple Access method and of estimating the channel quality in a system having a synchronization channel not orthogonal to a channel receiving data, a noise component of a desired channel is estimated; degree of a noise component caused by the synchronization channel is estimated with respect to the estimated noise; and a channel quality of a receiving channel is detected based on the estimated degree of the noise component.

Abstract: A code division multiple access (CDMA) communication system using spread spectrum signaling over a communication bandwidth uses two different signal spectra generated using two different respective spreading code formats, such as NRZ code formatting and staggered Manchester code formatting, for respectively providing nonsplit spectra having a center peak and split spectra having a center null. The spectra are combined during transmission as a CDMA communication signal having a composite spectrum. The use of different code formats produces the composite spectrum of respective center peak and center null spectra that enables increased channel capacity.

Abstract: An apparatus and method for channel estimation and CP reconstruction in an OFDM-STBC mobile communication system are provided. An ISI canceller cancels ISI signal components from first and second received symbol sequences. A cyclicity restorer cancels ICI signal components from the ISI-cancelled first received symbol sequence and the ISI-cancelled second received symbol sequence. A recoverer acquires the recovered sequence estimates of the ICI-cancelled first received symbol sequence and the ICI-cancelled second received symbol sequence by decoding. The ICI cancellation of the ISI-cancelled first and second received symbol sequences and the ISI cancellation of the second received symbol sequence are iterated a predetermined number of times.

Abstract: The invention provides an adaptive frequency hopping spread-spectrum (FHSS) transmission system and method, which efficiently utilizes available transmission bandwidth, whilst providing robustness to jamming techniques in wireless communication systems. The proposed technique operates by transmitting a wide-band signal over multiple, single-carrier, parallel transmission subbands, which may occupy non-contiguous frequency regions. The proposed scheme exhibits significant gain in error rate performance, as compared to a data rate equivalent single-subband system in the presence of signal jamming and/or interference without a reduction in the transmission data rate nor an increase in transmitter power. In addition, the proposed system and method are adaptive and enable more efficient use of the available bandwidth for communicating, thus increasing the overall bandwidth utilization of the system.

Abstract: A method and a standard radio wave receiver for receiving a plurality of standard radio waves respectively having signal configurations in accordance with respective specifications which define carrier channels and formats and for decoding time code signals carried by the standard radio waves. The method extracts at least part of a bit waveform common to the specifications as a extracted signal from a waveform of each of the time code signals given by each of the carrier channels, synchronizes bits to each of the time code signals in accordance with the extracted signal, determines an evaluation index indicating good or bad of a reception condition for each of the carrier channels from the bit waveform, and selects a single channel from the carrier channels in accordance with the evaluation index.

Abstract: An ultra wideband (UWB) receiver system operable to process a high order Gaussian pulse includes an integrator group, a correlator circuit and a comparator circuit. The integrator group includes an input coupled to receive the high order Gaussian pulse and an output coupled to the correlator circuit, the integrator group having two or more successively coupled integration stages, each integration stage operable to integrate, over a predefined time period, the signal received thereby, the integrator group operable to output, in response, a lower order Gaussian pulse. The correlator circuit is coupled to receive the lower order Gaussian pulse, and is operable to output a correlated output signal corresponding to the correlation between the lower order Gaussian pulse and a predefined reference signal.

Abstract: In a radar system, a monopulse calibration table is constructed from live targets of opportunity. A center of gravity or weighted average of normalized signals ?V received at SUM and DIFF channels from a live target are used to determine the target's actual azimuth. Off bore sight angles (OBA) of the target are then determined from the target's actual azimuth. Normalized received signal values of ?V are converted to nearest-valued integers. The OBA s that correspond to each integer-valued normalized received signal are averaged and can then be plotted as a function of normalized received signal value ?V. Different tables or plots can be constructed for elevation angles. An equation of a best-fit line the matches or at least closely approximates the plotted data is determined to smooth the actual data.

Abstract: A method is presented for packet detection and symbol boundary location using a two-step sign correlation procedure. When the correlation crosses a threshold, a packet detection signal is generated to initiate processing of downstream blocks, and a symbol boundary location signal is generated for use in aligning data during processing.

Abstract: The invention relates to a spread-signal multiplexing circuit for frequency-multiplexing a plurality of spread signals that were generated in parallel according to the SSMA scheme. An object of the invention is to adapt to various degrees of multiplicity and to keep the SN ratio and the power efficiency high. To this end, a spread-signal multiplexing circuit of the invention comprises an amplitude monitoring part for multiplexing a plurality of spread signals and determining amplitude of a resulting signal in time-series order; a delaying part for delaying the spread signals in parallel by a time that is equal to a propagation delay time of the amplitude monitoring part; and a multiplexing part for generating a multiplexed signal by multiplexing the delayed spread signals while weighting the delayed spread signals in parallel using weights that are smaller as an average value of the determined amplitude is larger.

Abstract: A method of generating a composite signal includes the steps of: (a) generating a plurality of sub-carriers, each sub-carrier having a different frequency position in a frequency spectrum; (b) generating a plurality of codes; and (c) forming a plurality of code combinations from the plurality of codes generated in step (b). The method also includes the steps of (d) first modulating each sub-carrier using a respective one of the code combinations formed in step (c) to form a plurality of modulated sub-carriers; and (e) second modulating in-phase and quadrature components of a base carrier using the plurality of modulated sub-carriers to form the composite signal having multiple carriers. The composite signal is a constant envelope signal, and a single sideband signal.

Abstract: A monopulse radar operating at low angles of elevation (LOE) receives returns from a target by a direct path and by a path including a reflection from that portion of the Earth's surface lying between the radar and the target. The surface-reflected signal tends to cause errors in the estimate of the elevation of the target. A radar system directs at least upper and lower overlapping beams at LOE toward the target for receiving returns. The upper and lower beams may be sequential or simultaneous. Real and imaginary portions of the sum (?) and difference (?) signals are generated for each beam. The monopulse estimates of elevation ê derived from the real portion of the ? and ? signals are processed to produce correction signals for upper and lower beams. Each correction signal is weighted and summed to correct the estimate of elevation.

Abstract: The number of times for averaging operation for averaging a correlation value of a received signal and a reference signal is properly controlled. When the correlation value is not averaged, since a lower limit value TH_A of a correlation level of a distribution of timings of which a path exists is larger than an upper limit value TH_B of a correlation level of a distribution of timings of which a path does not exist, the correlation value of a path is hidden by noise. Since the averaging operation is repeated until the relation of TH_A>TH_B is satisfied, the averaging operation is stopped when the relation is satisfied. The TH_A and TH_B are decided in accordance with RSCP and ISCP of a pilot channel and RSSI of a received base band signal.

Abstract: An integrated circuit implements a wireless remote sensor. The wireless remote sensor includes an antenna coupled to an energy distribution unit to allow passive collection of electrical charge. A signal processing unit couples to the energy distribution unit and modulates transmission by the antenna according to a binary code.

Abstract: A method of Partial Parallel Interference Cancellation (PPIC) is provided for recursively eliminating the Multiple Access Interference from a received signal. Such method is to use a recursion way to eliminate all the Multiple Access Interference (MAI) one by one from the received signal. Moreover, the present invention is to take the output of the pre-stage as the input of the present stage with the recursion method so that we can use only one operating circuit to obtain the function the MAI eliminating.

Abstract: A system for generating a pseudomonopulse tracking error includes an antenna system (401) that generates a sum antenna beam and a difference antenna beam. The sum antenna beam has a pattern with a peak gain on the boresight axis, and the difference antenna beam has a pattern that is circularly symmetric and forms a null about the boresight axis. The difference antenna beam has a relative phase that varies 360 degrees around the boresight axis. A differential phase dispersion is provided as between the sum and difference RF channels (405, 407) to providing a rotating scanning plane (702).

Abstract: System for dynamically tracking a position of a target with an antenna in a communication system. The system includes an antenna system (410) configured for generating a sum and difference antenna pattern (201-1, 201-2). A sum RF channel (401) is coupled to a sum channel output of the antenna system. A difference RF channel (402) is coupled to a difference channel output of the antenna system. An RF coupler (422-1) is provided that has a first input coupled to the sum RF channel and a second input coupled to the RF difference channel. One or more coupling control devices (418-1, 418-2) selectively vary an effective coupling value as between the difference channel and the sum channel. An antenna tracking error signal is generated at an output of the coupler.

Abstract: This monopulse processor provides target position information having an RMS error which is less than that of a conventional monopulse processor. A ?±j? vs. ? processor is modified to provide a position output signal equal to the smaller in absolute magnitude of the results obtained from the ?+j? vs. ? and the ??j? vs. ? processing. A conventional monopulse processor is modified to provide an output signal having a value equal to Re(?/?)/[1+|Im(?/?)|].

Abstract: The system and method for radar calibration using antenna leakage is a simplified means of calibrating the channels in amplitude and phase using natural signal leakage between antennas. It utilizes as calibration signal a wideband sinusoidal Frequency Modulated Continuous Wave (FMCW) waveform with a modulation index and modulation frequency chosen to generate spectral components (or discrete signal frequencies) that fall within the receiver Doppler passband of the radar. The calibration signal is radiated out of the transmitting antenna and enters the radar receiver front-end through the transmit-to-receive antenna leakage which occurs naturally. This technique provides a low-complexity (simpler hardware realization) means for achieving a wideband calibration rapidly and is a practical alternative to the conventional calibration approach that relies on generating offset Doppler signals that are coupled into the radar receiver front-end through the use of couplers and cabling within the radar.

Abstract: An invention is provided for determining the azimuth pointing angle of a moving monopulse antenna. Pulses of energy are broadcast at the surface of a planetary body. Reflected signals are received from the surface of the planetary body using a plurality of feeds. A monopulse ratio is then calculated based on a sum pattern and a difference pattern. The sum pattern is based on the sum of the reflected signals received using the feeds, and the difference pattern is based on a difference of the reflected signals received using the feeds. An azimuth pointing angle of a monopulse antenna is then calculated using the monopulse ratio.

Abstract: A monopulse radar system generates elevation and azimuth difference monopulse estimates of the location of targets in each range cell, where the target may be either a single or plural target, each of which is made up of multiple scattering sources. Each azimuth-elevation estimate is based on a transmitted pulse or burst at a given frequency, different from other frequencies in a set of pulses or bursts. A test statistic is generated for each set. The statistic relates to the shape in an azimuth-elevation plane of the cluster of estimates. The test statistic is compared with a threshold to decide whether a single target or plural targets exist in the range cell.

Abstract: To realize a monopulse radar system wherein the velocity of a mobile body, distance between an obstacle and the mobile body and relative velocity can be detected and simultaneously, the direction of the obstacle can be detected, in a monopulse radar system wherein an azimuth is detected depending upon amplitude difference or phase difference between signals respectively received by plural receiving antennas, an array antenna composed of plural antenna elements is used for each transmitting antenna and each receiving antenna, at least one of the transmitting antenna and the receiving antenna is provided with an antenna switch for switching an antenna beam shape to a short angle/long distance or a wide angle/short distance and a switch control device that controls the switching of the antenna switch is provided.

Abstract: An in-phase/quadrature component (IQ) mixer is configured to reject returns from a negative doppler shift swath in order to mitigate corruption of returns of a positive doppler shift swath. The mixer includes a sample delay element which produces a quadrature component from the in-phase component of an input signal. Further included are a plurality of mixer elements, a plurality of low pass filters, a plurality of decimators, and a plurality of all pass filters which act upon both the in-phase and quadrature components of the input signal. Also, a subtraction element is included which is configured to subtract the filtered and down sampled quadrature component from the filtered and down sampled in-phase component.

Abstract: A method, apparatus, and processing system for radar detection and tracking of a target using monopulse ratio processing comprising the following steps. First, receiving a signal comprised of a plurality of sum azimuth beams and difference azimuth beams. Then staggering the received signal. Next, filtering and localizing a clutter signal which is a portion of the received sum and azimuth beams. Then adaptively forming a sub-array sum azimuth beam and a sub-array difference azimuth beam from the filtered output to cancel the clutter. The adaptive beam forming including the determination of a sum and difference beam weight where the adaptive weight be equated to a product of the weight and the respective covariance matrices of the sum and difference beams, the product having no constraint points.

Abstract: A pulse Doppler radar receiver is disclosed wherein monopulse sum and difference signals are time-multiplexed and passed through a single gain-controlled amplifier channel for normalization, the sum signal being processed to provide both a D.C. gain control signal for such channel and a reference signal for demodulating the difference signal.

Abstract: A method for processing radar return data to determine a physical angle, in aircraft body coordinates to a target, is disclosed. The radar return data includes a phase difference between radar return data received at an ambiguous radar channel and a left radar channel, a phase difference between radar return data received at a right radar channel and an ambiguous radar channel, and a phase difference between radar return data received at a right radar channel and a left radar channel. The method includes adjusting a phase bias for the three phase differences, resolving phase ambiguities between the three phase differences to provide a signal, and filtering the signal to provide a physical angle to the target in aircraft body coordinates.

Abstract: A radar receiver is shown wherein the frequency of a first local oscillator is changed to bring an intermediate frequency signal representative of a moving target into frequency coincidence with a signal from a reference oscillator of fixed frequency.

Abstract: A method, apparatus, and processing system for radar detection and tracking of a target using monopulse ratio processing comprising the following steps. First, receiving a signal comprised of a plurality of sum azimuth beams and difference azimuth beams. Then staggering the received signal. Next, filtering and localizing a clutter signal which is a portion of the received sum and azimuth beams. Then adaptively forming a sub-array sum azimuth beam and a sub-array difference azimuth beam from the filtered output to cancel the clutter. The adaptive beam forming including the determination of a sum and difference beam weight where the adaptive weight be equated to a product of the weight and the respective covariance matrices of the sum and difference beams, the product having no constraint points.

Abstract: To realize a monopulse radar system wherein the velocity of a mobile body, distance between an obstacle and the mobile body and relative velocity can be detected and simultaneously, the direction of the obstacle can be detected, in a monopulse radar system wherein an azimuth is detected depending upon amplitude difference or phase difference between signals respectively received by plural receiving antennas, an array antenna composed of plural antenna elements is used for each transmitting antenna and each receiving antenna, at least one of the transmitting antenna and the receiving antenna is provided with an antenna switch for switching an antenna beam shape to a short angle/long distance or a wide angle/short distance and a switch control device that controls the switching of the antenna switch is provided.