Abstract: There is provided a calculation device for a radar apparatus which is configured to specify a direction of a target based on respective reception signals of a plurality of antennae. A calculation unit is configured to use a predetermined estimation algorithm of estimating angles of targets corresponding to a preset separable-number from the respective reception signals, set an arbitrary separable-number to generate a mode vector from the estimated angles of the targets, obtained by the predetermined estimation algorithm, and determine whether the set separable-number is proper or not based on a magnitude of an orthogonal component calculated from the mode vector and an input vector of the respective reception signals.

Abstract: Embodiments of the present invention generally relate to motion compensation, and in particular to an autofocus-based compensation (ABC) systems and methods for a ground moving target indication platform. According to one embodiment, a method for autofocus based compensation of range data acquired from an object in motion is provided. The method may include: receiving range data; steering at least one receive beam of the range data in a desired direction; transforming the range data into the range domain; determining the width of a main clutter lobe; excluding data that is not part of the main lobe clutter response; transforming the main-lobe clutter response into the range domain; calculating a phase correction term; and applying the phase correction to the original range data.

Abstract: One embodiment of the present invention relates to a radar transmitter comprised within a single integrated chip substrate, which is capable of continuous beam steering of a transmitted radar beam as well as an option to change the physical position of the origin of the transmit radar beam. The radar transmitter has a signal generator that generates an RF signal. The RF signal is provided to a plurality of independent transmission chains, which contain independently operated vector modulators configured to introduce an individual phase adjustment to the high frequency input signal to generate separate RF output signals. A control unit is configured to selectively activate a subset of (e.g., two or more) the independent transmission chains. By activating the subset of independent transmission chains to generate RF output signals with separate phases, a beam steering functionality is enabled. Furthermore, the subset defines a changeable position of the transmitted radar beam.

Abstract: In one embodiment, an active array antenna device includes: M (M?2) bandpass filters to filter signals received by M antenna elements; M low noise amplifiers to amplify the filtered received signals; M distributors to distribute respective of the M amplified signals into N (N?2) distributed signals; M sets of N phase shifters provided for respective of the M distributors to shift phases of the N distributed signals; M sets of N attenuators to attenuate N phase-shift signals; N beam synthesis circuits provided for N sets of the M attenuators to synthesize a beam by summing attenuator outputs from the M attenuators corresponding to the M distributors; a heat insulating container accommodating the low noise amplifiers and the receiving filters and formed of a superconductor material; and a cooler to cool the receiving filters and the low noise amplifiers to make the receiving filters in a superconducting state.

Abstract: An active antenna array is arranged to activate subsets of switchable elements causing the antenna to form a first beam having a first beam pattern, and later to form a second beam having a second beam pattern of substantially identical far field radiation pattern to the first beam pattern but with different origins. A receiver receives radiation reflected from a target back to the antenna when the antenna is configured with the first beam pattern and then when configured with the second beam pattern, and compares the phase of the radiation received at the receiver when the antenna is configured with the first beam pattern with the phase of the radiation received at the receiver when the antenna is configured with the second beam pattern to provide a phase difference signal. A target locating means determines the angular location of the target from the phase difference signal.

Abstract: An integrated circuit for transmit and receive matching is described. The integrated circuit includes a transmit amplifier. The transmit amplifier includes a first transistor, a second transistor and a first inductor. The first inductor couples the first transistor to the second transistor. The integrated circuit also includes a low noise amplifier. The low noise amplifier includes a third transistor, a fourth transistor, the first inductor, a second inductor, a third inductor and a transformer. The second inductor couples the first inductor to the third transistor. The third inductor couples the third transistor to ground.

Abstract: Provided is a radar apparatus including an envelope detector unit that acquires an envelope component of a signal transmitted from a receiving antenna in at least one combination of a plurality of combinations of transmitting antennas and receiving antennas whose spatial phases become equal to each other in the array antenna; a determination unit that determines an amount of compensation in the at least one combination based on the envelope component acquired by the envelope detector unit; and a compensator unit that compensates a phase of a signal transmitted from each of the receiving antennas before aperture synthesis by using the amount of compensation determined by the determination unit, or compensates a phase of a signal radiated from the transmitting antenna in another combination.

Abstract: A radar apparatus including a transmit/receive antenna having a plurality of channels, a comparator coupled to the antenna channels for providing receive signal sum and difference channels, a radar receiver, a coupler for coupling the sum and difference channels to the radar receiver, a radar transmitter for providing a signal to be transmitted, a coupler for coupling the transmitter to a cross-channel port of the comparator, and an adjuster for adjusting a phase length of at least one antenna channel so that when the apparatus is transmitting, the transmitted signals from the antenna channels have a specified relative phase relationship.

Abstract: A ground based avian radar receive antenna is implemented using a vertically oriented offset parabolic cylindrical antenna. The desired azimuth beamwidth is determined by the width of the parabolic cylinder reflector surface and the desired elevation beamwidth by the height of the parabolic cylinder reflector surface. A vertical array of antenna elements is mounted along the vertical focal line to provide electronic scanning in elevation. Low sidelobe levels are obtained using tapered antenna element illumination. Low cost modular construction with high reflector accuracy is obtained by attaching a thin metal reflector to thin ribs machined or stamped in the shape of the parabolic cylinder reflector surface. The antenna is enclosed in a radome and mechanically rotated 360 degrees in azimuth.

Abstract: Arbitrarily deploying scanning polarized RF reference sources and using them to establish a full position and angular orientation reference coordinate system or a full angular orientation reference coordinate system that objects property equipped with polarized RF sensors could use to determine their angular position and/or orientation relative to the reference coordinate system.

Abstract: A method for determining an angular orientation of a sensor relative to a source. The method including: amplitude modulating at least two synchronized polarized Radio Frequency (RF) carrier signals with a predetermined relationship between their amplitude modulation of their electric field components and their polarization states to provide a scanning polarized RF reference source with a desired scanning range, pattern and frequency; detecting the scanning polarized RF reference source at the sensor; and using peak detection or pattern matching analysis on a signal detected at the sensor to determine the angular orientation of the sensor relative to scanning polarized RF reference source.

Abstract: Methods of forming a downlink beam in an adaptive antenna system of a communications system that may reduce inter-system and/or intra-system interference include receiving vectors of signals including signals transmitted by user terminals of the communications system and signals transmitted by transceivers of an independent communications system, obtaining spatial information for the user terminals of the communications system and the transceivers of the independent communications system, generating complex transmitting weights that form spatial nulls directed at the transceivers of the independent communications system, and transmitting a downlink communications signal using the complex transmitting weights. Related systems are also disclosed.

Abstract: An antenna array for radar transceivers, in particular for ascertaining distance and/or speed in the surroundings of vehicles, a first antenna part being situated on a carrier and a second antenna part being situated on another carrier situated at a distance from the first. The first antenna part has two generally rectangular primary exciter patches which adjoin each other on one edge, where they are short-circuited toward ground, two primary exciter patches have two separate supply lines, and the second antenna part comprises two mutually separated rectangular secondary exciter patches, which partially cover the primary exciter patches and which have, in the region of the ground short-circuit of the primary exciter patches, in the beam direction, a distance from each other that at least exposes the ground short-circuit.

Abstract: A broadband blazed array has a plurality of elements. The elements are arranged side-by-side in a non-parallel spaced apart fashion with center-to-center spacing between adjacent elements being identical along cross-sections of the array that are aligned with the array's endfire directions.

Abstract: A method for determining an angular orientation of a sensor relative to a source. The method including: amplitude modulating at least two synchronized polarized Radio Frequency (RF) carrier signals with a predetermined relationship between their amplitude modulation of their electric field components and their polarization states to provide a scanning polarized RF reference source with a desired scanning range, pattern and frequency; detecting the scanning polarized RF reference source at the sensor; and using peak detection or pattern matching analysis on a signal detected at the sensor to determine the angular orientation of the sensor relative to scanning polarized RF reference source.

Abstract: The invention relates to an imaging method with synthetic aperture for determining an incident angle and/or a distance of a sensor from at least one object in space, wherein at each of a number of aperture points one echo profile is sensed. Advantageously, for several angles assumed as the incident angle, one phase correction value and/or one distance correction value is calculated, adapted profiles are generated based on the echo profiles by adapting the phase with the phase correction value for each assumed angle and/or by shifting the distance with the distance correction value, for the assumed angle, the adapted profiles are summed or integrated, and a probability distribution is derived, and a probability value for the incident angle and/or for the distance is determined therefrom. A determination of the incident angle is also possible independently of the distance, wherein it is possible to only consider velocities or accelerations.

Abstract: An airborne radar device having a given angular coverage in elevation and in azimuth includes a transmit system, a receive system and processing means for carrying out target detection and location measurements. The transmit system includes: a transmit antenna made up of at least a first linear array of radiating elements focusing a transmit beam, said arrays being approximately parallel to one another; at least one waveform generator; means for amplifying the transmit signals produced by the waveform generator or generators; and means for controlling the transmit signals produced by the waveform generator or generators, said control means feeding each radiating element with a transmit signal. The radiating elements being controlled for simultaneously carrying out electronic scanning of the transmit beam in elevation and for colored transmission in elevation.

Abstract: A method of providing a polarized radio frequency scanning source is provided. The method including amplitude modulating at least two synchronized polarized radio frequency (RF) carrier signals with a predetermined relationship between their amplitude modulation of their electric field components and their polarization states to provide a scanning polarized RF reference source with a desired scanning range, pattern and frequency. The two or more synchronized polarized RF carrier signals with the predetermined relationship between their amplitude modulation can obtain a periodic or non-periodic scanning range, rate and frequency.

Abstract: A true time delay beamforming system and calibration method for transmission and reception of a beam is disclosed. The true time delay beamforming system comprises at least one input signal received by at least one signal conditioning device, wherein the signal conditioning device is adapted to provide selective, independent, and variable control of one of a phase delay, a time delay and an amplitude of the input signal to produce an output signal. A control logic device is adapted to provide a control logic signal to the at least one signal conditioning device for selectively activating and controlling the signal conditioning device. The true time delay beamforming system may further include an automatic calibration system that generates an error correction signal based on errors detected in the output signal, and selectively adjusts the control logic signal based thereon.

Abstract: A device and a method for the improved directional estimation and decoding by means of secondary radar signals. The device includes: at least one array of antenna elements; a low noise first amplifier and bandpass filter combination connected to a plug-in connector S of the respective antenna elements; a first linear amplifier being connected at a filter output of said combination for amplifying the band-limited signal; a mixer connected to the first linear amplifier for the frequency conversion into a ZF region; a second linear amplifier and bandpass filter combination connected to the mixer output for amplifying and limiting the bandwidth of the signal in the ZF region; a first analog-to-digital converter connected to the second bandpass filter; a configurable signal processor connected to the first analog-to-digital converter; and a processing unit connected to the configurable signal processors.

Abstract: This invention describes new and improved phased shifted injection oscillator, a phased shifted injection locked push-push oscillator and a phased array antennas (PAA). The PAAs in accordance with an exemplary embodiment of the present invention are low cost, and therefore can be used in various commercial applications, such as wireless communication or satellite mobile television.

Abstract: According to one embodiment, bias estimation and orbit determination include receiving measurements in real time. The measurements include radar measurements and radar array orientation measurements. The radar measurements are generated by a radar system and indicate the location of a target. The radar array orientation measurements are generated by a navigation system and indicate the orientation of a radar array of the radar system. A state variable set is used. The state variable set includes measurement variables and dynamic bias variables. For example, a state variable set may include orbit position, orbit velocity, radar orientation, and radar measurement variables, which in turn may include dynamic bias variables such as orientation bias variables and measurement bias variables. A measurement variable is associated with a measurement, and a dynamic bias variable is associated with bias of a measurement.

Abstract: An antenna device includes an antenna substrate and a feed line substrate. The antenna substrate includes subarray antennas, feeding interfaces and a back surface. The subarray antennas are arranged parallel with an interval on a plane. Each subarray antenna includes antenna elements and first feed lines. The first feed lines feed signals from the feeding interface on back surface to the antenna elements. The feed line substrate is attached along back surface and includes second feed lines, first and second mode transformers. Each second feed line has one and other ends portions. Other end portion has wider width than one end portion. Each first mode transformer is located in one end portion and connected to the feeding interface. Each second mode transformer is located in other end portion. One end portions are arranged in a line with interval, and other end portions are alternately arranged across one end portions.

Abstract: A method of determining an angular orientation of a sensor relative to a source including the steps of amplitude modulating at least two synchronized polarized Radio Frequency (RF) carrier signals with a predetermined relationship between their amplitude modulation of their electric field components and their polarization states to provide a scanning polarized RF reference source with a desired scanning range, pattern and frequency; detecting the scanning polarized RF reference source at the sensor; and determining the orientation of the sensor based on the detected scanning polarized RF reference source. Similar methods are also provided for determining an angular orientation and/or position of a sensor relative to two or more sources, aligning a mobile sensor relative to a source and homing a sensor relative to a predetermined plane and/or point.

Abstract: A radar apparatus has a plurality of receiving antennas and an array transmitting antenna controlled to successively vary the direction of a transmitted beam within a range which includes a target detection range of directions. The direction of any target within the target detection range is detected based on a phase difference between incident reflected waves of adjacent receiving antennas. To eliminate false targets resulting from aliasing, each detected target is authenticated based upon closeness of its detected direction to the current transmitted beam direction. The receiving antennas and transmitting antenna are configured to exclude directions of grating lobes of the transmitted beam from the detection range, and thereby suppress effects of received reflected waves that originate from grating lobes.

Abstract: A surveillance apparatus (100) is provided, said apparatus including a linear sub-array (101) of N omnidirectional transmitter elements (103) and a planar sub-array (102) of M receiver elements (104). A plurality of the transient elements (105) are generated by separating out at each of the receivers (104) the signals transmitted from the antenna elements (103) of the transmitter sub-array (101). This allows the geometry of each path (from each transmitter antenna element, to the point being imaged and back to the receiver antenna elements) to be converted to a delay or phase shift to focus on the particular point being imaged. The transient elements (105) form a cylindrical array (106) at the mid points between transmitter and receiver sub-arrays. Such a configuration enables a full 360 degrees of cover in azimuth and typically +/?60 degrees in elevation.

Abstract: A radar system, including: a compact, active phased array antenna for transmission and reception of a focused radiation beam, circuits for providing signals to produce or detect a radiation beam by the phased array antenna and to control or detect the direction of the radiation beam, and wherein the radar is adapted to be mounted on a missile and scan a selected area proceeding the direction of motion of the missile.

Abstract: A system for a mobile ad-hoc communications network includes a single antenna aperture and a phased array antenna comprising a plurality of radiators communicating electromagnetically via the single antenna aperture. The system may also include a control circuit communicatively connected to the phased array antenna. The control circuit may include a communications module for transmitting and receiving communication data via the phased array antenna through the single antenna aperture and a radar module for transmitting and receiving radar signals via the phased array antenna through the single antenna aperture.

Abstract: In one embodiment, an ultra wide band (UWB) radar includes: a substrate; a plurality of antennas adjacent the substrate, the plurality of antennas being arranged into a plurality of sub-arrays; an RF feed network adjacent the substrate, the RF feed network coupling to a distributed plurality of amplifiers integrated with the substrate, wherein the RF feed network and the distributed plurality of amplifiers are configured to form a resonant network such that if a timing signal is injected into an input port of the RF feed network, the resonant network oscillates to provide a globally-synchronized RF signal across the network; a plurality of pulse-shaping circuits corresponding to the plurality of sub-arrays, each pulse-shaping circuit being configured to receive the globally-synchronized RF signal from the network and process the globally-synchronized RF signal into pulses for transmission through the corresponding sub-array of antennas; and an actuator for mechanically scanning the UWB radar so that the pulse

Abstract: An antenna device includes subarray antennas including antenna elements, feeding lines and feeding interfaces. At least one of the feeding lines includes a phase shifter which shifts phases of the signals feeding to corresponding antenna elements. The feeding lines feed signals to the antenna elements. Each feeding interface is connected to each of subarray antennas. The subarray antennas are arranged parallel to each other with an interval on a plane to be symmetrical about a central axis. The interval is less or equal than a free-space wavelength. The central axis is along with the center of two adjacent subarray antennas arranged at middle of the subarray antennas when the number of the subarray antennas is even. Moreover, the central axis is along with one subarray antenna arranged at the middle of the subarray antennas when the number of the subarray antennas is odd.

Abstract: A scanning radar system suitable for detecting and monitoring ground-based targets includes a frequency generator, a frequency scanning antenna, and a receiver arranged to process signals received from a target so as to identify a Doppler frequency associated with the target. The frequency generator generates sets of signals, each set having a different characteristic frequency, and includes a digital synthesiser arranged to modulate a continuous wave signal of a given characteristic frequency by a sequence of modulation patterns to generate one set of signals. The frequency scanning antenna cooperates with the frequency generator to transceive radiation over a region having an angular extent dependent on the generated frequencies.

Abstract: A phased array radar system comprising a plurality of radiating elements configured in a common array aperture for detecting and tracking targets; and a transmit and receive arrangement responsive to a first control signal for configuring the plurality of radiating elements to define a plurality of sub-apertures from the common array aperture for detecting and tracking short range targets, wherein the plurality of sub-apertures are independently steerable array apertures and include an amplitude taper applied across each of the plurality of sub-apertures to reduce a peak sidelobe level.

Abstract: In a radar device including a transmitting unit for transmitting a transmission signal having plural modulation sections, a receiving unit for receiving a reflection signal obtained through reflection of the transmission signal from a target by an array antenna having plural channels, a mixing unit for mixing the transmission signal with reception signals of the plural channels to obtain beat signals of the plural channels, a frequency analyzing unit for frequency-analyzing the beat signals of the plural channels, and a direction calculating unit for calculating the direction to the target on the basis of frequency analysis results of the plural channels, the direction calculating unit adds correlation matrixes generated from peak frequency spectra of the plural modulation sections to obtain an summed correlation matrix, and calculating the direction to the target on the basis of the summed correlation matrix.

Abstract: In a radar system, harmonic excitation of an antenna is carried out in different frequency ranges. The antenna characteristic which varies as a function thereof is used to analyze different solid angle ranges around an object.

Abstract: A system (200) and method (400) for determining the location of an object is provided. A plurality of radio transceivers (101,201,203,205) are disposed about a location of interest (221). One or more tags (102) are coupled to an object. The radio transceivers (101,201,203,205) transmit radio frequency signals (115,215,217,219) to the tag (102), which backscatters a return signal (116,216,218,220) having a unique identifier modulated therein due to a switch (108) switching between two or more loads (110,112) in accordance with a unique identification code (118). A location determination module (107) then determines the location of the tag (102) by using a course location estimate (502), a fine location estimate (503), or combinations thereof. A object modeling module (109) can create multidimensional models using the locations of the tags (102).

Abstract: A radar sensor having multiple antenna elements for transmitting and receiving radar signals, an associated transmitting and receiving element and an evaluation device for determining the azimuth angle of located objects on the basis of a relationship between the signals received from different antenna elements, wherein the transmitting and receiving element is designed to supply to the antenna elements transmission signals in parallel, the frequencies of which are offset with respect to one another, and the evaluation device is designed to distinguish between signals that were transmitted by different antenna elements on the basis of the frequency offset.

Abstract: Embodiments of the invention are concerned with a radar system, and relates specifically to scanning radar systems that are suitable for detecting and monitoring ground-based targets.

Abstract: A system and method for warning a helicopter of an approaching bullet using existing sensor systems is disclosed. The disclosed method including the steps of: detecting and providing bearing information for detected small arms weapon firing locations near the helicopter, determining a detection area and detection time window for the fired bullet, determining the antennas of the RF transmitting and RF receiving systems covering the bearing of the detected weapon firing; determining a timing sequence and allocating time segments for transmitting and receiving RF signals during the detection time window, commanding the RF emitting system to emit and the RF receiving system to receive RF signals during their allocated time segments, processing RF signals received and determining whether reflected RF signal pulses from the emitted RF signal pulses are present, and outputting a warning where reflected RF signal pulses are detected.

Abstract: For detection of an electromagnetic signal, which is transmitted from a transmitting antenna (1), by means of at least two at least essentially identical receiving antennas (3, 4), whose sensitivity curve has a maximum (M) with falling flanks as well as sidelobes (SL) adjacent to it with sensitivity increased again at a reception angle symmetrically with respect to a basic alignment, with angle determination for an object which reflects the transmitted signal being carried out by the two receiving antennas (3, 4) by phase determination in an unambiguous interval (?u) whose boundaries (L) are predetermined by the distance (d) between the receiving antennas (3, 4), the distance (d) is chosen such that the boundaries (L) of the unambiguity area (?u) intersect the sidelobes (SL), and the reflective object is detected by means of vectorial addition of the signals from the receiving antennas (3, 4), after which the parameters R, v are determined.

Abstract: A method to compensate for radar platform angular motion may include measuring or estimating any radar platform angular motion. The method may also include substantially decoupling each array subsection response of a plurality of array subsection responses from any radar platform angular motion by applying continuous time varying phase adjustments to each individual array subsection response, prior to forming composite array Sum and monopulse Delta beam responses The time varying phase adjustments may be determined in response to any radar platform angular motion measured or estimated.

Abstract: A phased array radar system comprising a plurality of radiating elements configured in a common array aperture for detecting and tracking targets; and a transmit and receive arrangement responsive to a first control signal for configuring the plurality of radiating elements to define a plurality of sub-apertures from the common array aperture for detecting and tracking short range targets, wherein the plurality of sub-apertures are independently steerable array apertures.

Abstract: A method for generating a multiresolution decomposition of an array signal by a bank of spatial bandpass filters is disclosed. The signal processing operation is implemented through the use of the directivities of the individual array elements and does not degrade the spatial or temporal resolution of the array.

Abstract: A system for differentiating between a signal from a physical source and a nonlinear signal effect includes an array, a delay control element and a signal processing element. The array is configured to detect a signal at a particular location using an initial time delay. The delay control element is configured to modify the initial time delay by a selected value and to apply a phase delay in an amount equal to the selected value and at a frequency of the signal. The signal processing element is configured to determine whether the signal corresponds to one of a physical source or a nonlinear signal effect based on whether a shift in a perceived location of the signal occurs.

Abstract: A low profile mobile in-motion antenna and transmit/receive terminal system for two-way “VSAT” type satellite communication using FSS service, preferably in Ku band, supporting at the same time TV signal reception from the same satellite or a separate DBS satellite located at the same or nearby geo-stationary orbital position.

Abstract: A system and method for an electronically scanned antenna is provided in which phase shifters are deposited en masse along with other electronically scanned antenna components on a wafer scale substrate using a thin film process. Alternative wafer scale sizes may be utilized to furnish a required antenna aperture area. Significant processing costs for radar and communication systems are saved utilizing the present invention as compared with contemporary discrete phase shifters that are individually mounted on an antenna. In an aspect, the phase shifter is made up of a base electrode, a barium strontanate titanate (BST) ferroelectric varactor and a top electrode. The BST ferroelectric material is a voltage variable dielectric, which generates a radiation phase. The radiation phase is regulated by a phase shifter control. The radiation phase generates an electromagnetic field about a radiating element and electromagnetic radio waves are radiated from the radiating element.

Abstract: A concept is described for broadening the beam of a phased array radar antenna to provide continuous illumination of all radar targets within the search space, and this beam is compressed upon reception to realize the angular resolution that is possible with the antenna. The process is analogous to pulse compression. The advantages of the long dwell times provided by this concept include superior clutter suppression performance, more accurate tracking of targets, and the ability to analyze the target returns for reliable discrimination, classification and identification. The broad beam also reduces the power seen by an intercept receiver, for increased covert operation. This is all accomplished without any sacrifice in power. Various embodiments are disclosed.

Abstract: A radar system having a processor, a waveform generator, a plurality of antenna interfaces, a set of first antennas configured to transmit a waveform, and a set of second antennas configured to receive a reflected waveform is disclosed. The waveform generator and antenna interfaces are in control and signal communication with the processor, each of the first antennas are in signal communication with one of each antenna interface, and each of the second antennas are in signal communication with one of each antenna interface. The waveform generator is in control and signal communication with each antenna interface, and is configurable to generate a waveform conforming to at least two ISM bands. Each first antenna is configured to transmit a circularly polarized electromagnetic waveform, and each second antenna is configured to receive a reflected circularly polarized electromagnetic waveform complementary to the first antennas.

Abstract: The present invention provides an electric wave axis adjusting apparatus for an on-vehicle radar capable of readily and precisely adjusting an electric wave axis only by making the scanning range and a detection range identical to each other and changing a scanning range, and of adjusting the electric wave axis of an on-vehicle radar without wasting time in order to detect a reflector.

Abstract: A radar apparatus and a radar signal processing method can prevent misdetection even in the case of targets running side by side without an azimuth angle error being varied in accordance with the velocities of the targets. An antenna direction control part controls the direction of an antenna so as to vary the directions of radar beams at the time of observation in up phases and at the time of observation in down phases. An azimuth angle calculation section of a signal processing part calculates azimuth angles in up and down phases, and an azimuth angle determination section of the signal processing part selects an output content of observation data concerning a target to be detected from the amplitude of a difference between the azimuth angles in up and down phase.

Abstract: A radar system having a beamless emission signature is described. In one implementation, the radar system includes a transmission system and a receiver system. The transmission system is configured to transmit a pattern comprising a plurality of radar signals having different frequencies simultaneously. The receiver system is configured to receive a reflection of the pattern and combine the plurality of radar signals into a composite waveform forming an image of a target.