Abstract: A phased array anti-jamming device, comprising a plurality (N) of antennas and a plurality of splitters connected to the antennas and adapted to split an RF stream received from the antennas. The phased array anti-jamming device further includes at least one digital signal processor adapted to digitally analyze a digital output of digital processing channels and to split the output into a plurality of digital down converted representations of respective analog outputs of a plurality of analog digital processing channels in a plurality of different frequencies and calculate at least one instructions selected from phase shift, amplification, and attenuation instructions for each one of the plurality of antennas per each one of the plurality of different frequencies. The phased array anti-jamming device further includes a plurality of phase shifter groups a plurality of group combiners and a main combiner adapted to sum outputs of the plurality of group combiners.

Abstract: A collision avoidance system includes a monopulse radar antenna array of monopulse radar antenna segments mounted to a vehicle with respective fixed fields of view. Each monopulse radar antenna segment comprises a comparator network configured to form a sum signal representing a summation of return signals and a first difference signal representing a first difference of the return signals. The system further includes a user interface configured to present information in a form perceptible to a person operating the vehicle and a radar antenna array controller configured to calculate a range of the object and a first (azimuth) angle of arrival of the return signal from the object. The comparator network is further configured to form a second difference signal which the radar antenna array controller uses to calculate a second (elevation) angle of arrival.

Abstract: In an embodiment, a method of interference mitigation in a device that includes a millimeter-wave radar, includes transmitting radar signals with the millimeter-wave radar; receiving reflected radar signals with the millimeter-wave radar, the reflected radar signals corresponding to the transmitted radar signals; generating a first spectrogram based on the reflected radar signals; generating a second spectrogram indicative of movement of a non-target object; generating a compensated radar spectrogram based on the first and second spectrograms to compensate for an influence of the movement of the non-target object in the first spectrogram; and detecting a target or a property of the target based on the compensated radar spectrogram.

Abstract: A GNSS hostile environment simulator for accurate real-time processor & hardware in the loop (PHIL) simulations of a multiple antenna GNSSR/AJ system models antenna effects over the entire signal bandwidth allowing direct injection of the RF into the GNSSR. Computational efficiency is achieved by applying the antenna patterns in the frequency domain. To preserve the integrity of the antenna signals, the transmitter signals are generated over an extended period to push any residual ringing outside the update window. Efficiency is further enhanced by using a combination of single-precision and double-precision floating-point units to generate the samples of the transmitter signals with single-precision floating-point. All subsequent calculations are then computed in single-precision.

Abstract: A system comprises a plurality of antenna elements arranged in a two-dimensional array, and a plurality of transmitter circuits communicatively coupled to the antenna elements, wherein the antenna elements and transmitter circuits are configured such that desired components of signals output by the plurality of transmitter circuits and radiated via the antenna elements coherently combine in a desired direction. Each of the transmitter circuits is operable to generate a corresponding second signal for transmission via a respective one of the antenna elements by shifting a phase of undesired components in the signal relative to a phase of desired components in the signal.

Abstract: An operation method of a terminal in a wireless communication system includes: transmitting uplink (UL) traffic information indicating a size of a UL data signal to a base station; receiving a jamming message generated based on the UL traffic information from the base station; generating an uplink (UL) transmission signal including the UL data signal and a UL jamming signal based on the jamming message; and transmitting the UL transmission signal to the base station. Also, the jamming message indicates a pattern of the UL jamming signal, the UL transmission signal is transmitted in a same frequency band as a frequency band in which a downlink (DL) transmission signal of the base station is received, and the UL jamming signal is transmitted in remaining resources excluding resources occupied by the UL data signal in the frequency band.

Abstract: An apparatus is disclosed for current-mode filtering with switching. In an example aspect, the apparatus includes a filter including two input nodes, two output nodes, two differential paths, two bypass nodes respectively coupled between the two input nodes and the two output nodes along the two differential paths, a high-pass filter coupled between the two bypass nodes and the two output nodes, two low-pass switches, a band-pass switch, and a low-pass filter coupled in series with the high-pass filter along the two differential paths. The high-pass filter includes two series capacitors, which are respectively coupled between the two bypass nodes and the two output nodes, and two shunt inductors, which are respectively coupled to the two bypass nodes. The two low-pass switches are respectively coupled in parallel with the two series capacitors. The band-pass switch is coupled in series between the two shunt inductors.

Abstract: A radar system suitable for an automated vehicle includes a radar sensor and a controller. The radar-sensor is mounted on a host-vehicle. The radar-sensor is operable to detect radar-signals reflected by scattering-points of a target-vehicle located proximate to the host-vehicle. The controller is in communication with the radar-sensor. The controller is configured to determine a present-range-rate, a present-azimuth, and optionally a present-range, of each of the scattering-points at a present-time. The controller is also configured to recall a prior-range-rate, a prior-azimuth, and optionally a prior-range, of each of the scattering-points at a prior-time. The controller is also configured to calculate a yaw-rate of the target-vehicle at the present-time based on the present-range-rate, the present-azimuth, the prior-range-rate, and the prior-azimuth, and optionally the present-range and the prior-range, of each of the scattering-points.

Abstract: A computer-implemented method is provided for filtering clutter from a radar signal received by an antenna. The method includes determining a transient clutter voltage at first and second times separated by a time interval, determining a clutter correlation for the time interval, and dividing a received signal correlation by the clutter correlation. In alternate embodiments, the clutter correlation can be combined with a noise correlation and the sum divided by the signal correlation.

Abstract: A radio frequency identification (RFID) system includes an RFID interrogator and an RFID tag having a plurality of information sources and a beamforming network. The tag receives electromagnetic radiation from the interrogator. The beamforming network directs the received electromagnetic radiation to a subset of the plurality of information sources. The RFID tag transmits a response to the received electromagnetic radiation, based on the subset of the plurality of information sources to which the received electromagnetic radiation was directed. Method and other embodiments are also disclosed.

Abstract: An antenna apparatus for a radar sensor having a plurality of individual antenna devices that interact through interference to generate and/or receive a radar beam at a predetermined angle of transmission and/or reception. The individual antenna devices are provided with a radar signal and are arranged such that a first angle of transmission and/or reception of the radar beam is determined via an analog beam formation and a second angle of transmission and/or reception of the radar beam is determined via a digital beam formation. The antenna apparatus further includes a feed device configured to generate the radar signal. In addition, the radar beam can be electronically pivoted. Also, an aircraft can include the antenna apparatus.

Abstract: A radar system includes a transmit antenna array having subarrays disposed at predetermined positions. An orthogonal waveform signal is directed to a corresponding one of the subarrays. On receive, an adaptive processor derives a plurality of adaptive weight factors from a plurality of receive signals and applies them to the receive signals to obtain a jammer cancelled signal. That signal is separated into its orthogonal waveform components by passing it through a bank of correlators. The correlator system provides a plurality of unique receive signals substantially corresponding one-to-one to the unique transmit subarrays. The receive beamformer derives an angular estimate of at least one target relative to boresight from the unique receive signals.

Abstract: Certain aspects of the present disclosure relate to a hybrid approach for Physical Downlink Shared Channel (PDSCH) Interference Cancellation (IC). In certain aspects, if the PDSCH information is known for a serving cell but not be known for interfering cell(s), a hybrid approach that involves using Codeword-level IC (CWIC) for the serving cell and using Symbol-level IC (SLIC) for the interfering cells may be used for better IC performance. The hybrid IC approach may start with a UE attempting to decode the serving cell PDSCH. If the decode is unsuccessful, the UE may perform CWIC for the serving cell followed by SLIC using the results of the CWIC stage. After the SLIC stage, the UE may attempt to decode the serving cell PDSCH again. The UE may perform multiple operations of this method until the serving cell PDSCH is successfully decoded or a maximum number of iterations is reached.

Abstract: Interference detection involves detecting the interference component in the received signal if there is such a component, controlling a band reject filter according to the detected interference component to filter the received signal to suppress the interference component, and synchronizing the receiver to the received signal, wherein the step of detecting the interference component is started before synchronization is achieved. By starting the interference detection without waiting for synchronization to be achieved, rather than following the synchronization, then the interference detection is no longer dependent on the synchronization being achieved.

Abstract: A method that digitally distinguishes mainlobe detections from grating lobe and sidelobe detections without need for added antenna or receiver architecture. The method includes applying receive weights to return radar data for each radar receive element to steer each subarray of a array radar antenna to a direction other than the subarray transmit angle and includes applying a subarray weight to each subarray to generate the array radar antenna receive beam data having magnitude and phase components. The method includes applying predetermined scale factors to the subarray beam data magnitude for each subarray to generate scaled subarray beam data magnitudes. The method includes generating guard beam data for each subarray based on the scaled subarray beam data magnitudes. The method also includes determining if the return radar data corresponds to a mainlobe or a grating lobe or sidelobe based on the receive beam data and the guard beam data.

Abstract: A system and method of radar location comprises radar signal emission means, an emitted pulse of duration T1 and index i starting at instant T2(i); means receiving reflected radar signals; means determining correlation between reconstruction of an emitted pulse and signal received during the time interval between T2(i)+2*T1 and T2(i+1). The means determining a correlation can reconstruct a set, of at least one truncated pulse j of duration T3(j), less than T1, corresponding to the final part of said emitted pulse, said truncated pulses having increasing respective durations, determining at least one first correlated signal j by correlation of said truncated pulse j and signal received during time interval between T2(i)+T1 and T2(i)+T1+T3(j) and determining a second signal, based on first correlated signals j, by copying the time interval, of said correlated signal j, between T2(i)+T1+T3(j) and T2(i)+T1+T3(j+1), onto the time interval, of said second signal, between T2(i)+T1+T3(j) and T2(i)+T1+T3(j+1).

Abstract: A Global Positioning System (GPS) signal reception apparatus including a GPS antenna unit, a GPS signal selection unit, and a jamming signal detection unit is provided. The GPS antenna unit includes a first-type antenna and a plurality of second-type antennas which have directivities different from each other. The GPS signal selection unit selects any one of the first-type antenna and the plurality of second-type antennas as a selected antenna. The jamming signal detection unit detects a jamming signal present in a GPS signal by analyzing the GPS signal which is received via the selected antenna.

Abstract: According to an embodiment of the present invention jamming energy is allocated to a plurality of emitters based on a three-dimensional (3-D) emitter geolocation technique that determines the geolocation of radio frequency (RF) emitters based on energy or received signal strength (RSS) and/or time differences of arrival (TDOAs) of transmitted signals. The three-dimensional (3-D) emitter geolocations are used to rank emitters of interest according to distance and available radio frequency (RF) jamming energy is allocated to the emitters in rank order. The techniques may be employed with small unmanned air vehicles (UAV), and obtains efficient use of jamming energy when applied to radio frequency (RF) emitters of interest.

Abstract: Provided is an audio coding apparatus and method that can selectively apply a operation mode of a coding module for stereo or multi-channel representation according to input signal characteristics of each channel, when voice or music signals are transmitted using an audio codec in portable terminals capable of stereo or multi-channel input and output. The audio coding apparatus includes a down-mixer for down-mixing multi-channel audio signals into mono signals; a coder for coding the mono signals; an input channel correlation analyzer for deciding whether to give them stereo effect based on their signal distribution characteristics, and outputting a control signal indicating whether to perform stereo representation process; and a stereo representation unit for performing stereo representation process onto the multi-channel audio signals when the control signal indicating to perform stereo representation process.

Abstract: A method and apparatus for detecting a jammer comprising sampling an input signal; downconverting and sampling the input signal to generate a sampled downconverted (SD) input signal; comparing the sampled input signal to a wideband threshold THWB, and comparing the SD input signal to a narrowband threshold THNB; generating a wideband (WB) interrupt signal based on the comparison to the THWB, and generating a narrowband (NB) interrupt signal based on the comparison to the THNB; and generating a composite interrupt signal based on at least one of WB interrupt signal and NB interrupt signal. In one aspect, the apparatus comprises a wideband jammer detector for generating a WB interrupt signal to indicate a wideband jammer; a narrowband jammer detector for generating a NB interrupt signal to indicate a narrowband jammer; and interrupt logic for generating a composite interrupt signal based on one of WB interrupt signal and NB interrupt signal.

Abstract: A Global Positioning System (GPS) signal reception apparatus including a GPS antenna unit, a GPS signal selection unit, and a jamming signal detection unit is provided. The GPS antenna unit includes a first-type antenna and a plurality of second-type antennas which have directivities different from each other. The GPS signal selection unit selects any one of the first-type antenna and the plurality of second-type antennas as a selected antenna. The jamming signal detection unit detects a jamming signal present in a GPS signal by analyzing the GPS signal which is received via the selected antenna.

Abstract: The present invention relates to a method for cleaning signals for centralized antijamming. The invention makes it possible to provide as many cleaned antenna channels as sub-arrays with limited computational requirements. The method proceeds in two steps. Initially, an antijamming matrix is computed. This matrix depends on the noise covariance matrix, on a weighting vector representing the form of the desired antenna pattern on reception in an unjammed environment, and on constraints for preserving the shape of this antenna pattern. Subsequently, the signals arising from the antenna sub-arrays undergo a linear recombination effected by the antijamming matrix. The antijamming method is termed centralized since the data necessary for the antijamming processing are concentrated in the lone antijamming matrix. The invention applies notably to radar systems, notably to airborne radar systems.

Abstract: A method for prioritizing threats to an aircraft is disclosed. The method can include providing threat attribute information including a threat engagement timeline and a threat lethality metric and obtaining a threat track indication that indicates a threat is tracking the aircraft. The method can also include determining a historical position estimate of the aircraft at which the threat track began, a time estimate at which the threat track began and determining a period of time during which the threat track has been possible. The method can also include determining a time to engagement based on the threat attribute information and the time period and calculating a priority value for the threat based on the time to engagement and the threat lethality metric. The method can include outputting a prioritized threat list including the priority value calculated for the threat.

Abstract: There is provided an apparatus for capturing cosmic background radiation and for converting cosmic background radiation into electricity. An antenna is configured so as to capture cosmic background radiation. An electrostatic electron multiplier is connected to the antenna. A high voltage power supply is connected to the electrostatic electron multiplier whereby cosmic background radiation is converted to electricity.

Abstract: A receiver that selectively samples a received signal in order to suppress an interference component of the signal while recovering a desired component. The selective sampling may be accomplished by low cost, low complex analog or digital circuitry. The receiver includes a first input that receives a first signal, including a desired signal component and an interference signal component and a second input that receives a second signal including the interference component only. The first and second signals are then provided to the sampling circuitry. First, the phase of the interference component of the both the first and second signals is aligned. Next, the points in a wave cycle that the second signal is at a power minimum are detected. Finally, first signal is sampled close to the point when the second signal is at the power minimum to recover the desired signal component and suppress the interference component.

Abstract: Cognitive anti-jam receiver systems and associated methods are provided. The systems and methods may include a signal analysis module that processes a baseband signal to determine one or more signal characteristics of the baseband signal, the baseband signal comprising at least a desired signal; a cognitive decision unit that receives the one or more signal characteristics from the signal analysis module, and generates at least one first adaptive parameter; and at least one anti-jam processing module that processes the baseband signal to generate a modified signal that reduces an impact of at least one jammer signal on a quality of reception of the desired signal from the baseband signal, where processing by the at least one anti-jam processing module may be based at least in part on the received at least one first adaptive parameter from the cognitive decision unit.

Abstract: The invention includes, in its various aspects and embodiments, a method and apparatus for detecting cross-eye jamming. In some embodiments, the invention includes mitigating cross-eye jamming once its presence is detected.

Abstract: The present invention relates to a method for cleaning signals for centralized antijamming. The invention makes it possible to provide as many cleaned antenna channels as sub-arrays with limited computational requirements. The method proceeds in two steps. Initially, an antijamming matrix (M) is computed. This matrix depends on the noise covariance matrix (?), on a weighting vector (wr) representing the form of the desired antenna pattern on reception in an unjammed environment, and on constraints (C, f) for preserving the shape of this antenna pattern. Subsequently, the signals (xi) arising from the antenna sub-arrays undergo a linear recombination effected by the antijamming matrix (M). The antijamming method is termed centralized since the data necessary for the antijamming processing are concentrated in the lone antijamming matrix (M). The invention applies notably to radar systems, notably to airborne radar systems.

Abstract: A single chip radio transceiver includes circuitry that enables detection of radar signals to enable the radio transceiver to halt communications in overlapping communication bands to avoid interference with the radar transmitting the radar pulses. A method in a radio transceiver includes grouping a plurality of pulse data entries, generating a first list of pulse repetition intervals having pulses with a pulse width within a specified range, counting a number of most and second most common pulse interval values and determining whether a radar signal is present. Generally, the method includes determining a radar is present in one of three different ways, namely, determining whether the number of the most common pulse interval values exceeds a specified value, determining a radar signal is present with an extra pulse and finally, determining a radar is present with a missing pulse.

Abstract: Jammer detection is operable in both continuous and burst modes, managing a jammer attack in both cases. Whether in continuous or burst mode, jammer presence is detected according to a burst jammer environment. Results of jammer presence detection are stored to create a history of the jammer presence, and the history is used to manage the jammer attack. Jammer detector thresholds are implemented with hysteresis, and a hysteresis pinch-off characteristic is mitigated.

Abstract: Jammer detection is operable in both continuous and burst modes, managing a jammer attack in both cases. Whether in continuous or burst mode, jammer presence is detected according to a burst jammer environment. Results of jammer presence detection are stored to create a history of the jammer presence, and the history is used to manage the jammer attack.

Abstract: The invention concerns an antenna system for level measurement with a level measurement device with a wave guide (5) that runs axially and that either has on its rear side an arrangement (4) for the generating and interpreting electromagnetic waves or can be connected to such an arrangement of an antenna, in particular, a parabolic antenna (1-3) on the front side of the wave guide and a wave adapter (9) for transmitting such a wave between two components of the arrangement that conduct the wave for adaptation of the wave transmission between the components, whereby the wave adapter has a through opening in the axial direction.

Abstract: A vehicle detector includes a detecting apparatus and a determining apparatus. If a plurality of detection points detected by the detecting apparatus forms a group of detection points, the determining apparatus sets a determining virtual window encompassing the group of detection points and determines whether the group of detection points is likely to represent the one vehicle based on a state of movement of the group of detection points with respect to the determining virtual window.

Abstract: Techniques for detecting and suppressing jammers are described. A receiver may perform post-FFT jammer detection and pre-FFT jammer suppression. The receiver may transform an input signal to obtain a frequency-domain signal and may detect for jammers in the input signal based on the frequency-domain signal. The receiver may determine powers of a plurality of carriers based on the frequency-domain signal and may detect for jammers based on peaks in the powers of these carriers. The receiver may filter the input signal (e.g., with a notch filter) to suppress the detected jammers. Alternatively or additionally, the receiver may perform post-FFT jammer detection and post-FFT jammer suppression. The receiver may determine whether jammer is present on each carrier based on data power and channel power for that carrier. The receiver may modify (e.g., zero out or reduce) the frequency-domain signal on carriers with detected jammers.

Abstract: A mobile receiver apparatus is provided where its antenna directivity is controllably determined for improving the response to a desired signal as it moves and its surrounding geographical features and thus its environment for signal reception are varied. The mobile receiver apparatus comprises a directivity variable antenna, an antenna controller connected with the directivity variable antenna for conducting a control action to align the directivity with a desired direction, and an optimum directivity calculator connected with the antenna controller for calculating from the current position of a mobile and its surrounding geographical features an optimum pattern of the directivity.

Abstract: An adaptive antenna array has array elements arranged in element rows and element columns and subarrays arranged in subarray rows and subarray columns, for which the subarray phase centers have non-uniform spacing. The adaptive antenna array provides good detection and tracking performance when used in a radar system, while being inexpensive and easy to manufacture. A radar system and a method of adapting a radar array both employ the above described adaptive antenna array.

Abstract: An improvement in monopulse radar achieves nulling of a single mainlobe jammer and multiple sidelobe jammers while maintaining the angle measurement accuracy of the monopulse ratio by cascading a multiple sidelobe canceller and a mainlobe canceller, and imposing a mainlobe maintenance technique during the sidelobe jammer cancellation process so that the results of the sidelobe jammer cancellation process do not distort the subsequent mainlobe cancellation process. In this manner, the sidelobe jammers and the mainlobe jammer are cancelled sequentially in separate processes.

Abstract: This invention relates to radar signal processing. In particular, this invention concerns signal processing of agile Pulse Repetition Time (PRT) sampled signal transmitted using spread spectrum technique. This invention solves, in particular, the incompatibility between Doppler processing and spread spectrum such providing an improved anti-jamming technique without narrowing the Doppler range. The method for deconvolution comprises combining the pulses with the same carrier in a burst, transforming the obtained signals from time to frequency domain, and deconvolving the obtained spectra. In a first embodiment of this invention, such a deconvolution method is adapted to irregular PRT sampled signal comprises an irregular samples to regular zero-padded samples conversion step between the combination and the transformation steps.

Abstract: A system employs null angle measurements developed in response to the detection of radiation, such as jamming, along with the positions at which the null angles are measured, to determine the location of the radiation source through reverse triangulation.

Abstract: The invention relates to a method of interference suppression in a radar system (10) and also to a system (10) operating according to the method. The system (10) incorporates a first antenna (40) and associated electronic circuits for emitting interrogating radar radiation towards a remote scene (S). Moreover, the system (10) also incorporates a second antenna (45) and associated electronic circuits for receiving interrogating radiation reflected from the scene (S) and generating correponding first and second processed signals. The first and second processed signals correspond to a broader main beam response of the antenna (45) and to a narrower main beam response thereof respectively. By mutually comparing the first and second processed signals, the system (10) is operable to identify those second processed signals affected by interference from the scene (S).

Abstract: An apparatus for electronic warfare signal simulation which is used in an external test system to simultaneously test a plurality of “victim” communication systems for vulnerability to jamming. The test system includes a remote radiator of a signal free of jamming effects, and a remote radiator of one or more radio frequency control signals which represent one or more predetermined jamming threats in the low and mid bands.

Abstract: This invention relates to radar signal processing. In particular, this invention concerns signal processing of agile Pulse Repetition Time (PRT) sampled signal transmitted using spread spectrum technique. This invention solves, in particular, the incompatibility between Doppler processing and spread spectrum such providing an improved anti-jamming technique without narrowing the Doppler range. The method for deconvolution comprises combining the pulses with the same carrier in a burst, transforming the obtained signals from time to frequency domain, and deconvolving the obtained spectra. In a first embodiment of this invention, such a deconvolution method is adapted to irregular PRT sampled signal comprises an irregular samples to regular zero-padded samples conversion step between the combination and the transformation steps.

Abstract: In a method of suppressing jammer signals in the received signal of radar antennas of HPRF applications (such as pulse Doppler radar systems) by means of Fast Fourier Transformation and side lobe cancellation, the receiving radar antenna has a sum channel, a difference channel and an auxiliary channel. The received signal is first transformed in the sum, difference and auxiliary channels from the time domain into the frequency domain using a Fast Fourier Transformation (FFT). Subsequently, the the jammer signal, particularly the side lobe jammer, is suppressed in the frequency domain by means of side lobe cancellation.

Abstract: In regard to radar guidance of a launch container (15) for fragmentation projectiles (16) for defending against an attacking missile (12), from the object (11) to be protected, the present invention affords a radar guidance system which can be inexpensively set up from existing components and which, in the absence of interfaces between the object (11) and the launch container (15), operates in a trouble-free manner if, for space monitoring and target acquisition, provided on the substructure (14) of the launch container (15) which is fixed with respect to the object, there is a planar antenna (20) which transmits its target information to a target-tracking radar (19) which is integrated into the launch container (15), for directly guiding the launch container (15) on to the approach of the missile (12) to be defended against.

Abstract: In a method of suppressing jammer signals in the received signal of radar antennas of HPRF applications (such as pulse Doppler radar systems) by means of Fast Fourier Transformation and side lobe cancellation, the receiving radar antenna has a sum channel, a difference channel and an auxiliary channel. The received signal is first transformed in the sum, difference and auxiliary channels from the time domain into the frequency domain using a Fast Fourier Transoformation (FFT). Subsequently, the the jammer signal, particularly the side lobe jammer, is suppressed in the frequency domain by means of side lobe cancellation.

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: The invention relates to a method of interference suppression in a radar system and also to a system operating according to the method. The system incorporates a first antenna and associated electronic circuits for emitting interrogating radar radiation towards a remote scene. Moreover, the system also incorporates a second antenna and associated electronic circuits for receiving interrogating radiation reflected from the scene and generating corresponding first and second processed signals. The first and second processed signals correspond to a broader main beam response of the antenna and to a narrower main beam response thereof respectively. By mutually comparing the first and second processed signals, the system is operable to identify those second processed signals affected by interference from the scene.

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 radar system and technique provide the capability to detect a target of interest and maintain the detection in the presence of multiple mainlobe and sidelobe jamming interference. The system and technique utilize digital beamforming to form sub-arrays for canceling jamming interference. Jamming is adaptively suppressed in the sub-arrays prior to using conventional deterministic methods to form the sum, &Sgr;, and difference, &Dgr;, beams for monopulse processing. The system and technique provide the ability to detect a target of interest, provide an undistorted monopulse ratio, m, and maintain target angle estimation, in the presence of multiple mainlobe and multiple sidelobe jammers.

Abstract: Generating a secondary beam (11) slightly offset from the main data collection beam (9) and obtaining hot clutter reference to be used in a conventional side lobe jammer processing algorithm (31). Advantage is taken of the typical geometries of a standoff jammer (1) which provides nearly matched dispersion characteristics of the jammer RF when viewed with the two received beams. The important parameter is dispersion relative to the received bandwidth. The secondary beam, which may be identical copy of the main beam except for target information, is placed offset by approximately two beam widths toward the jammer. The offset distance is chosen so that there is minimal and preferably no overlap in the main beam footprint on the ground but is as close as possible thereto. If there is overlap, then there is a chance that the target will appear in both beams and therefore be suppressed.