Abstract: A need exists for a method to do monopulse tracking with a single beam phased array antenna. With a monopulse tracker antenna, the satellite, or moving target, will have a beacon signal that the tracker can acquire. The beacon signal may be a preamble in the transmitted signal from the satellite. The monopulse tracker antennas are scanned over the volume, minimizing the error signal. When the error signal is minimal, the antenna is pointed in the direction of the satellite or moving target. Because the tracker needs to know direction offsets in both azimuth and elevation planes, error signals from both planes are needed. The monopulse tracker antenna maintains a radio frequency link to the beacon signal, causing the antenna to lock in the direction of the satellite when the error signal is minimized to zero.

Abstract: A presence sensor device 8 for a building. The presence sensor device 8 is for detecting persons and includes a first radar sensor 14 and a second radar sensor 20. The first radar sensor 14 is arranged to operate with a first frequency band, a first power consumption, and a first range, with the second radar sensor 20 being arranged to operate with a second frequency band, a second power consumption, and a second range. The first frequency band is lower than the second frequency band and the first range is longer than the second range.

Abstract: In a frequency-offset self-injection-locked (FOSIL) radar, a first mixer is provided to mix a first oscillation signal of a first injection-locked oscillator (ILO) and a second oscillation signal of a second ILO so as to cancel out the frequency drifts of the first and second oscillation signals. Accordingly, the transmit frequency of the FOSIL radar can remain constant to mitigate the EMI issue.

Abstract: The present invention provides a radar device capable of reducing processing load while arraying receiving antennas in two directions. In the present invention, a transmitting unit (transmitting antenna) transmits an electromagnetic wave. A plurality of receiving antennas 108 receive a reflected wave from an object which reflects the electromagnetic wave, and convert the reflected wave into a first signal Sig1. A plurality of receiving circuits 520 are respectively connected to the receiving antennas 108 and generate a second signal Sig2 from the first signal Sig1. A signal processing unit 103 processes the second signal Sig2. The plurality of receiving antennas 108 are arrayed in a first direction and a second direction crossing the first direction.

Abstract: A communications device and a data receiving method thereof are provided. The communications device includes: a receiver antenna receiving data; a receiver phase shifter forming a first sum beam and a first difference beam based on a first estimated direction-of-arrival (DOA); a receiver radio frequency (RF) chain generating first difference beam output using the first difference beam formed during a first data period of the received data and generating first sum beam output using the first sum beam formed in a second data period of the received data, which is different from the first data period; and a receiver controller calculating an offset vector between an actual DOA and the first estimated DOA based on the first difference beam output and the first sum beam output.

Abstract: A weather radar with a transmission antenna array that outputs a high aspect ratio FMCW transmission beam that illuminates an area in the field of regard in elevation and may be electronically scanned in azimuth. The weather radar includes a receive array and receive electronics that may receive the reflected return radar signals and electronically form a plurality of receive beams that may be used to determine characteristics of the area in the field of regard. The receive beams may be used to determine reflectivity of weather systems and provide a coherent weather picture. The weather radar may simultaneously process the receive signals into monopulse beams that may be used for accurate navigation as well as detection and tracking of objects, such as birds, aircraft, UAVs and the like.

Abstract: A distributed radio access network (RAN) is provided. A selected wireless transceiver node(s) in a selected coverage cell receives a radio frequency (RF) test signal(s). The selected wireless transceiver node(s) determines an effective gain value based on a predefined characteristic of the RF test signal(s). The selected wireless transceiver node(s) communicates the effective gain value and other related parameters to a server apparatus in the distributed RAN. The server apparatus determines a common gain value for the selected wireless transceiver node(s) in the selected coverage cell based on the parameters. Accordingly, the selected wireless transceiver node(s) operates based on the common gain value.

Abstract: An antenna includes a substrate, a first array of transmit antenna patches on the substrate, and a second array of receive antenna patches on the substrate. A spatial orientation of the first array with respect to the second array is selected based on a predetermined desired radiation coupling between the first array and the second array. The antenna can be part of an automotive radar sensor.

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: An array antenna forms a main beam, and the main beam is toward a beam direction. The array antenna includes a plurality of radiating elements with a plurality of central line segments, where the plurality of radiating elements are arranged along a straight line, and the straight line is connecting the plurality of central line segments; and a plurality of meanders connecting the plurality of radiating elements; where the array antenna is disposed on a first plane, the beam direction has a nonzero deviating angle with a normal direction of the first plane, and the normal direction is perpendicular to the first plane.

Abstract: A dynamically configurable antenna is integrated into a system configured to transmit and receive data. Antenna control software and/or hardware configures the antenna to transmit and receive data with different operating characteristics, depending on the communication needs of the system. The physical structure of the dynamically configurable antenna can be modified in order to perform data communications with specific frequency ranges, directionalities, transmission and/or amplification powers, and other operating characteristics generally associated with wireless RF communication.

Abstract: A radar device for the transmission of a signal in a frequency band. The radar device includes a control means and an oscillator. The input of the oscillator is connected to the control means by means of a converter. The oscillator is controllable by means of the control means for the generation of the signal. The signal is generated by means of the oscillator and can be picked up on an output of the oscillator. The radar device also includes at least one transmission aerial for the transmission of the signal being present at the output of the oscillator. The transmission aerial is connected to the output of the oscillator. At least one receiver channel is provided for the reception of a received signal and for the processing of the received signal and for the transmission of the processed received signal to the control means. The receiver channel has at least one receiving aerial and a mixer for the mixing of the received signal with the signal which is present at the output of the oscillator.

Abstract: The present invention relates to a dual reflector antenna with a hybrid subreflector, and more particularly, to a dual reflector antenna with a subreflector having a structure in which an ellipse and a hyperbola are combined. An exemplary embodiment of the present invention provides a dual reflector antenna including: a main reflector; and a hybrid subreflector which faces the main reflector and has a first structure and a second structure which are combined therein.

Abstract: An electrically adjustable antenna control system includes a controller, an actuation mechanism controlled by the controller, and a feedback loop connected to both of the controller and actuation mechanism. Herein, the controller includes a control board and its imbedded program. The actuation mechanism includes a DC geared motor controlled by the control board and embedded program and an electrically adjustable antenna phase shifter driven by the geared motor. The feedback loop has a travel plate electrically coupled to both of the control board and DC geared motor and a counter device installed on the geared motor. The present invention also provides an electrically adjustable antenna control method realized by the above-mentioned electrically adjustable antenna control system.

Abstract: A dual monopulse/interferometer antenna and radar system. In one example, the antenna includes an active electronically steered monopulse array, and is configurable into an interferometer mode which uses a subset of the array elements of each quadrant of the monopulse array. In one example, the RF feed network that combines signals received from each element in the array to produce monopulse return signals is modified in the interferometer mode to couple out the subset of array elements to produce return signals that are analyzed using interferometric processing.

Abstract: A multiple beam receiving system provides an angle estimate to targets. The system tracks movements of the targets over time and generates calibration information. The system uses the calibration information to more accurately estimate angle-to-target. The multiple beam receiving system can be part of a monopulse or other radar system, a traffic collision avoidance system, or other electromagnetic sensor.

Abstract: A Luneburg lens is used in conjunction with a patch antenna array. The patch antenna array is conformed or adapted to cover a portion or backside of the Luneburg len's surface with the backplane of the conformed antenna array defining a field of regard (FOR) in which objects are detected and tracked. A processor is connected to a receiver/exciter module which connects to transmit/receive modules which are connected to the individual patch antennas through a network of MEMS switches. In a receive mode, selected subarrays of the conformed patch antenna array are scanned during selected time intervals with the sum and delta beams being formed coherently in amplitude and phase to realize amplitude monopulse sensing and angle tracking of an object.

Abstract: Embodiments of a target classifier and method for target classification using measured target epsilons and target glint information are generally described herein. The target classifier is configured to compare a total epsilon measurement with target glint information to determine whether to the target being tracked corresponds to an intended target type. Based on the comparison, the target classifier may cause target tracking circuitry of a target-tracking radar to either continue tracking the target or break-off from tracking the target. Glint of different target types may be characterized at different ranges and the target's glint characteristics may be used to distinguish intended from non-intended targets. Accordingly, intended targets such as incoming artillery may be distinguished from non-intended targets such as aircraft to help prevent countermeasures from being launched against non-intended targets.

Abstract: The disclosed approach provides a low-cost approach by employing a single channel receiver for a direction-finding missile, rather than a conventional four-channel system. It employs interferometry techniques. The proposed approach leverages orthogonal waveforms and pseudorandom noise (PN) codes. This is a low-cost approach for a single channel direction finding system by leveraging orthogonal waveforms and interferometric techniques.

Abstract: A radar device including: a reception antenna that receives radio waves, includes at least three antennas and is arranged so that the phase center points thereof form an isosceles triangle; an arrival direction detection unit that detects an arrival direction of the radio waves by a phase monopulse method; and a phase correction unit that corrects a phase difference between phases of radio waves respectively received by two adjacent antennas among the three antennas based on the relationship of the phases of the radio waves respectively received by the three antennas.

Abstract: Modern tactical radars frequently use phase shifters to electronically specify or steer the spatial position of the antenna beam without requiring mechanical motion of the antenna. These phase shifters can only be set correctly for a specific frequency. If a waveform is transmitted through the antenna which consists of multiple segments which differ in frequency or modulation from that frequency used to steer the position of the beam, errors are introduced into the monopulse measurement. These monopulse errors are reduced or eliminated by correction factors. The monopulse errors are corrected by pre-computed factors or terms which result from the differences in frequency and modulation used in the waveform from the frequency used to steer or position the beam. Correction is also provided for radar altitude. These correction factors are easily pre-computed and applied only when needed to minimize the computational requirements.

Abstract: The present invention relates to a method for determining the angular aperture corresponding to the extent in a plane of an object seen by a radar antenna, the object being situated at a given distance from the radar antenna. Echoes are measured in directions ? p - ?? 2 ? ? and ? ? ? p + ?? 2 of the plane, where ?p is a variable angle corresponding to directions of the plane and ?? is a given angular aperture. The pairwise differences are calculated between the echo measurements taken in the directions ? p - ?? 2 ? ? and ? ? ? p + ?? 2 . The slope is determined at a value ?p of a function e of ?p interpolated between the calculated differences, the angular aperture which corresponds to the extent of the object at the given distance being deduced from the slope. The invention has an application in meteorological radar.

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 system for estimating an antenna boresight direction. The novel system includes a first circuit for receiving a Doppler measurement and a line-of-sight direction measurement corresponding with the Doppler measurement, and a processor adapted to search for an estimated boresight direction that minimizes a Doppler error between the Doppler measurement and a calculated Doppler calculated from the estimated boresight direction and the line-of-sight direction measurement. The line-of-sight direction measurement is measured relative to the true antenna boresight, and the calculated Doppler is the Doppler calculated for a direction found by applying the line-of-sight direction measurement to the estimated boresight direction. In a preferred embodiment, the first circuit receives a Doppler measurement and a line-of-sight direction measurement from each of a plurality of pixels, and the processor searches for an estimated boresight direction that minimizes a sum of squares of Doppler errors for each of the pixels.

Abstract: Systems and methods are provided for extracting relative signal parameters representing two closely spaced targets from monopulse scan data. A maximum quadrature angle value from the scan data is compared with a threshold quadrature value representing a noise level. A linear polynomial model is utilized if the maximum quadrature angle exceeds the threshold value. The linear polynomial model fits a function of the azimuth angle values and quadrature angle values to a linear function of an exponential parameter derived from the boresight angles to produce polynomial coefficients and determines the relative signal parameters from the polynomial coefficients. A cubic polynomial model is utilized if the maximum quadrature angle fails to exceed the threshold value. The cubic polynomial model fits azimuth angle values to a cubic function of corresponding boresight angles to produce a set of polynomial coefficients and determines the relative signal parameters from the set of polynomial coefficients.

Abstract: An antenna is provided, in combination with an associated switch array, the antenna comprising a number of antenna elements mounted above a ground plane for providing coverage over a predetermined range of angles in azimuth using a number of beams. Each of the antenna elements is connected to a switch in the switch array and the switch array is operable to connect selected pairs of the antenna elements to a signal path to thereby generate each of the different beams, at the same time connecting unselected antenna elements to ground.

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 method and apparatus for electronically steering a RADAR beam across an array of feed horns by moving the phase center of the beam to different origination points on the array—each origination point being the phase center of a feed horn pair. Variations include polarized beams, polarized feed horns, dual-beam systems, dual direction steering, diagonal steering, and cross-polarized wire grids to control beamwidth.

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: An antenna unit includes at least one transmission antenna and plural reception antennas. A receiver detects information including azimuth information for a target, based on an output from the antenna unit. An antenna switching unit switches connections between a transmitter and the transmission antenna and between the reception antenna and the receiver. The antenna unit includes a wide-beam array antenna and plural narrow-beam array antennas having a narrower beam width than the array antenna. A monopulse process is performed based on an output of a predetermined pair of array antennas from among the array antennas formed as the narrow-beam array antennas.

Abstract: A monopulse radar tracking method which analyzes boresight error information provided a monopulse radar to determine a location for two targets. The monopulse radar tracking method analyzes the boresight error information to determine an angle of arrival for a dominant target and a secondary target.

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: A method and apparatus for generating accurate estimates of a radar target's azimuth and elevation angles for a phased-phased array rotating radar. Scan modulated coherently integrated (SMCI) monopulse curves are generated from a measured one-way transmit antenna pattern and three receive antenna patterns. The SMCI monopulse curves are calculated in advance for the expected beam steers. To utilize the SMCI monopulse curves, two-way Sum, Delta-Azimuth and Delta-Elevation target returns are coherently integrated, the target's monopulse ratios calculated, and the SMCI monopulse curves or polynomials used to calculate the target's U-offset and V-offset sine-space angles, which are added to the radar's beam steer to get an improved estimate of the target's sine-space angular position denoted as Utgt and Vtgt. A coordinate system transformation transforms Utgt and Vtgt to azimuth and elevation angles in a non-rotating coordinate system.

Abstract: Reducing antenna boresight error includes receiving radar pulses reflected from the ground, where pulses are emitted from the antenna of a radar system, reflected by the ground, and received by the antenna. The return pulses carry information about the ground. Measurement indices are established from radar and platform parameters, and a clutter spectrum is generated from the return pulse information. The amplitude of the clutter spectrum is measured at each of the measurement indices. Whether there is an amplitude imbalance is established in accordance with the measured amplitudes. An error estimate describing an antenna boresight error is determined if there is an amplitude imbalance.

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: A radar of the present invention has: (1) an antenna unit for transmitting a radio wave and receiving a reflected wave of the radio wave; (2) rotating means for rotating the antenna unit about an axis along a direction of transmitting the radio wave; and (3) control means for detecting an azimuth of a target from the reflected wave, the azimuth using the axis as a reference and being defined in a plane determined from a posture of the antenna unit and the axis.

Abstract: A digital signal gating method and apparatus of a preprocessor in a detection system wherein the detection system includes a central processing unit, a main memory and a receiver, whereby the apparatus and method bifurcate received digital signals, delays them along a first path while subjecting the digital signals along a second path to detection, delay, and thresholding and thereby generates a gating signal from the second path so that digital signals of the first path, including pre-threshold amplitudes, may be recorded.

Abstract: Reducing antenna boresight error includes receiving radar pulses reflected from the ground, where pulses are emitted from the antenna of a radar system, reflected by the ground, and received by the antenna. The return pulses carry information about the ground. Measurement indices are established from radar and platform parameters, and a clutter spectrum is generated from the return pulse information. The amplitude of the clutter spectrum is measured at each of the measurement indices. Whether there is an amplitude imbalance is established in accordance with the measured amplitudes. An error estimate describing an antenna boresight error is determined if there is an amplitude imbalance.

Abstract: A radar tracking system for an anti-aircraft, missile, including angle tracking, doppler tracking and range tracking feedback loops operating on sum and difference channels. Fast fourier transform digital filters are used to provide a frequency spectrum of the sum and difference I.F. channels and detection and confirmation algorithms are employed for selecting the F.F.T. target ‘bin’. Adjacent F.F.T. bins are used to simulate a bin centered on the target frequency, shifts of the latter with target/missile acceleration causing frequency errors which are detected by a discriminator and used to control the target I.F. Confirmation of target acquisition is achieved by successive summations of the target bin power the totals being accumulated and compared with upper and lower thresholds. Confirmation and rejection results from total levels outside the thresholds while further accumulation and comparison follow the intermediate condition.

Abstract: A method and apparatus for estimating elevation angle when using a broad search beam such as a cosecant-squared beam is provided. The range of a target detected during a search with a broad beam covering a broad angular search area is determined. Based on the determined range, consecutive beams are transmitted at increasing search elevation angles in the broad angular search area. Echo signals of the consecutive beams are used to determine an elevation angle estimate for the target.

Abstract: A method for main beam alignment verification includes providing data pertaining to one or more patterns associated with an antenna, measuring power levels of a signal acquired by the antenna, and comparing the measured power levels with the data to determine whether a direction of the signal is incident upon a main beam of the antenna.

Abstract: A radar system derives a correction for an actual boresight (311) of a radar monopulse antenna mounted on a moving platform from ? data and ? data generated with respect to an a priori known, calibrated boresight (309). The monopulse antenna (602) is coupled to a ground position measuring system (616) while acquiring data. The radar receiver acquires a ? and ? synthetic aperture map of the same radar scattering location with respect to the calibrated boresight. ? SAR data and the ? SAR data are motion compensated using the position and velocity supplied by the ground positioning system. A computer forms a ratio of the aligned ? pixels to the aligned ? pixels for each of a plurality of aligned ? pixels located near the calibrated boresight. The correction for the location of the actual boresight of the monopulse antenna is computed by an analysis of the ratio of aligned ? pixels and corresponding aligned ? pixels over the radar scattering location.

Abstract: A monopulse radar system for detecting an azimuth depending upon amplitude difference or phase difference between signals respectively received by plural receiving antennas, includes: a transmitting array antenna and a receiving array antenna each including antenna elements forming an antenna train, at least one antenna switch disposed among the elements of the transmitting array antenna and/or the receiving array antenna, and a switch controller for turning ON/OFF the antenna switch to change an aperture length of the transmitting array antenna and/or the receiving array antenna thereby changing a beam shape thereof. The antenna elements of the transmitting array antenna and the receiving array antenna are formed on a dielectric substrate. A dielectric length between the antenna train formed by the antenna elements and the antenna switch is ½ dielectric wavelength.

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: A combined defense and navigational system on a naval vessel is disclosed. The disclosed system includes a track-while-scan pulse radar which is controlled to provide either navigational information or tracking information on selected targets. Additionally, the disclosed system includes a plurality of guided missiles, each of which may be vertically launched and directed toward intercept of a selected target either by commands from the track-while-scan radar or from an active guidance system in each such missile.

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: A system and method for detecting a radar target of interest in the presence of radar jamming interference include a sub-array beamformer, a sum and difference beamformer, a weight calculator, a composite beamformer, and a monopulse ratio calculator. A plurality of sub-arrays is formed from antenna array element data. Respective sum and difference beams are formed for each of the plurality of sub-arrays. A single weight is formulated from the sum and difference beams, respectively. Composite sum beams are formed in accordance with the sum weights and the sum beams, and composite difference beams are formed in accordance with the difference weights and the difference beams. Composite beams are formed such that at least one null of each of the composite beams is steered toward an interference and a boresight gain of each of the composite beams is maintained.

Abstract: A method for main beam alignment verification includes providing data pertaining to one or more patterns associated with an antenna, measuring power levels of a signal acquired by the antenna, and comparing the measured power levels with the data to determine whether a direction of the signal is incident upon a main beam of the antenna.