107 results about "Monopulse radar" patented technology

An implanted fluid access port locator system for adjustable gastric bands. The system may include an access port having an RFID tag with its antenna adjacent to the receiving portion of the port. An external locator with radio frequency transmitter/receiver circuitry sends read or interrogation signals to the RFID tag and may send write signals to the tag to write treatment data to memory of the RFID tag. The locator may include an antenna array with four patch antenna arranged in pairs to model two monopulse radar antenna systems. The locator also includes processor(s) and logic modules/circuitry for processing the tag response signals received by the antenna array to determine location information for the RFID tag and associated port, i.e., to identify the center of the port relative to the antennae array or array face such as with strength and direction information relative to the array face. A method of locating implanted fluid access port includes providing radio frequency transmitter/receiver circuitry on the access port and manipulating a handheld locator outside the body to pinpoint the position and orientation of the access port. A mark may be made with a handheld locator to direct insertion of a needle for adding or removing fluid from an implanted system through the access port.

A vehicle radar system and method for detecting objects are provided. The vehicle radar system includes a side radar sensor providing a detection area at a side of the vehicle and a rear radar sensor providing a detection area at a rear of the vehicle. Each of the side and rear radar sensors includes a monopulse radar device. The radar sensor system further includes a controller configured to control operation of the side and rear radar sensors.

The invention discloses a phased array monopulse radar system based on the time modulation antenna array technology. The basic scheme of the invention comprises an antenna array comprising a plurality of array antenna units, a high-speed radio frequency switch controlled by a complex programmable logic device, a radar receiver, and the like; based on the basic scheme, a power-divider, a mixer, and an intermediate frequency amplifier are reasonably added in the radar receiver, and an amplitude detector, a phase detector and the like are reasonably added at a data processing terminal to form various improved schemes of the invention. With the invention, sum beams and difference beams are easily generated simultaneously, therefore, the transmission of simultaneous frequency diversity signals can be easily realized, and difference beams of higher performance (beam gain, null depth, slope of zero, and the like) can be easily obtained. The invention can be widely used in the phased array monopulse radar systems having application background adding radar reconnaissance difficulty of enemy, or used in radar systems of other target angle measurement and precision angle tracking.

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.

A phased array, phase-amplitude monopulse antenna arrangement for ground, shipboard or airborne radar systems. The phased array antenna is systematically warped and projects partially overlapping, separate beams from upper and lower regions of the array. A single set of phase-shifters is employed with a simplified feed structure to permit development of both azimuthal and elevation angle error signals in signal processing circuitry for target analysis.

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.

It is possible to effectively configure an antenna system of simple structure in a limited space. A mono pulse radar device includes an antenna unit having an array antenna (wide-beam array antenna)(area K1) formed by a part of the antenna element as a constituting element of the antenna unit and narrow-beam array antennas formed with a narrower beam width than the array antenna. Mono pulse processing is performed according to an output of a predetermined pair of array antennas (areas K2, K3) among the plurality of array antennas formed as the narrow-beam array antennas.

The invention relates to the technical field of radar jamming, and discloses an adaptive cross-polarization active jamming method and device. The device comprises a receiving antenna, a transmitting antenna, a receiving module and a jamming control module, wherein the receiving antenna which is used for receiving horizontal or vertical polarized signals is connected with the jamming control module through the receiving module; the output end of the jamming control module is connected with the transmitting antenna which is used for transmitting horizontal or vertical polarized signals; and a receiving-transmitting isolation device is arranged between the receiving antenna and the transmitting antenna. According to the jamming device, the jamming effect generated when a plurality of jammers work at the same time can be achieved by one jammer without measuring pulse description words (PDW) of a radar signal or the polarized state of the radar signal and without adopting a plurality of jammers to run at the same time, and cross-polarization jamming can be generated adaptively, so that a stable and effective jamming effect can be achieved, the angle measurement accuracy of a monopulse radar can be greatly reduced, and the cost for development and maintenance can be greatly reduced.

An improved system is provided for aiming a shotgun-based or other countermeasure system so as to be able to countermeasure incoming rockets or projectiles. In one embodiment a shotgun aimed and controlled by the subject system projects a pattern of pellets to intercept a rocket-propelled grenade or incoming projectile. The fire control system uses a CW two-tone monopulse radar to derive range and angle of arrival within 150 milliseconds, with range and angle of arrival measurements having approximately twice the accuracy of prior CW two-tone monopulse radars. The improvement derives from using all of the information in the returned radar beams and is the result of the recognition that one can use the Sum and Difference signals to assemble a two-by-two Rank One matrix that permits using singular value decomposition techniques to generate range and angle of arrival matrices in which all available information is used and in which noise is eliminated.

A terrain aided navigation using multi-channel monopulse radar imaging to provide a navigation position update. The monopulse radar transmits a single RF pulse transmission or multiple quick RF pulse train bursts to generate a monopulse radar image that can be correlated with a digital terrain segment to provide navigation updates when requested. The radar has monopulse and off-axis capability that allows for selection of a terrain segment within the radar's search area that will provide a good terrain correlation. The radar measurements are made on a range/Doppler cell-by-cell basis that includes angle information. The cells in the range/Doppler map corresponding to the antenna main beam return are converted into a high resolution (x,y,z) image and correlated to the selected terrain segment in the data base reference frame to provide an updated navigation position estimate.

Method of automatic target angle tracking by sum-and-difference monopulse radar covers radiolocation sphere and specifically monopulse direction finding systems. It can be used in order to increase guidance accuracy, for example, for anti aircraft missiles and of unmanned aerial vehicles to radar targets such as: radio beacons; aerial vehicles reflecting the radio signal that illuminates them; aerial vehicles and ground-based devices radiating radio signals and jamming signals. The aim of the method consists in the assurance of reliability and stability and in the enhancement of guidance accuracy of automatic target angle tracking due to elimination of automatic tracking losses and great errors arising during the influence of the signals of orthogonal polarization or polarization close to it.

The proposed method provides full protection from polarization jamming for all types of monopulse radars.

The process is used for suppressing the effect of signals that are received or sent via side lobes of an antenna (PA; HA) of an amplitude or phase monopulse radar device, in which for the purpose of position measurement of a first and, if need be, a second target (T1, T2) detected by the radar beam, three illumination functions Je(Lx), Jk(Lx) and Js(Lx) for the antenna (PA; HA) are provided for each measurement axis, as well as antenna functions Fe(X), Fk(X), and Fs(X) resulting from them. The first, second, and third illumination functions Je(Lx); Jk(Lx), and Js(Lx) are selected in this connection so that a quotient function Qe(X)=Fe(X)/Fs(X) or Qk(X)=Fk(X)/Fs(X), which is linearly or quadratically dependent on the target direction, is produced by normalizing the first and the second antenna functions Fe(X); Fk(X) with the third antenna function Fs(X). The power of this quotient is compared with at least one threshold value the or thk that is selected in accordance with the magnitude of the main antenna lobe, and when the threshold value the or thk is exceeded, the effect of the received signal is suppressed. In a preferred embodiment of the invention, the provision is made that the zero points of the antenna functions Fe(X), Fk(X), and Fs(X) are shifted slightly in relation to one another.

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 signal indicative of the elevation angle.

The invention belongs to the technical field of radar electronic countermeasures, and discloses a method for detecting, distinguishing and suppressing cross-eye jamming by a single-pulse radar. The method is characterized in that two types of angle measuring methods are started to carry out angle measurement again when the single-pulse radar is subjected to the cross-eye jamming and loses a target, whether the cross-eye jamming exists or not is detected through comparing the difference of measured angles acquired by the two types of angle measurements methods, and the cross-eye jamming is suppressed through a method of tracking a jamming source if the jamming exists. The method disclosed by the invention is mainly applied to detecting and suppressing the cross-eye jamming, and influences imposed on the direction finding performance of the single-pulse angle tracking radar by the jamming are eliminated. The method can also be applied to various single-pulse radars or signal detecting, recognizing and tracking devices, thereby quickly recognizing the cross-eye jamming, improving a jamming recognition ability of the system, and effectively resisting the cross-eye jamming.

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

The invention relates to a double-channel monopulse radar tracking dynamic target aircraft real-time phase calibration method. The double-channel monopulse radar tracking dynamic target aircraft real-time phase calibration method comprises the following steps of step one performing advance preparation work; step two obtaining data at different moments; step three calibrating a phase deviation between a tracking sum path and a tracking different path. The double-channel monopulse radar tracking dynamic target aircraft real-time phase calibration method can solve the problem that a former double-channel monopulse radar requires to perform phase calibration through a static simulation target in advance before tracking and cannot perform real-time phase calibration during a process of tracking a dynamic target aircraft.

The invention discloses a method and system for detecting two-dimensional CFAR of a monopulse radar based on an FPGA. The method comprises the following steps of: A, designing a data pool, wherein thesize of the data pool is X*Y, X is a distance dimension, Y is the size of a reference window, a protection unit is set to be H, a detection factor is F, and a threshold is Z; B, judging whether a detection point is a boundary point or not, if not, executing C1, otherwise, executing C2; C1, calculating the comparison result of the energy values of the detected data in the upper direction, the lower direction, the left direction and the right direction, accumulating and multiplying F, comparing the product with Z, and if the product exceeds Z, taking the detected point as a target point; C2, dividing the upper direction, lower direction, left direction, and right direction of the detection unit into effective directions and invalid directions, wherein the number of the effective directionsis p; updating a threshold Z to p/4; calculating the comparison result of the energy value of the detected data in the effective directions, accumulating and multiplying F, comparing the product withZ, and if the product exceeds Z, taking the detected point as the target point. The method can effectively reduce false alarm; and the detection can be quickly and timely carried out when the reference window is larger.

An interference condition-based dual polarization monopulse radar object angle estimating method is disclosed and relates to the technical field of radar electronic countermeasures. A radar receiving antenna is transformed into a double polarization reception antenna, corresponding sum-difference networks and receiving channels are added, and a dual polarization monopulse radar device is formed; according to three channel sum, azimuth difference and pitching difference output data of horizontal polarization of the radar device as well as three channel sum, azimuth difference and pitching difference output data of vertical polarization, polarization characteristics of compound jamming can be estimated, a polarization ratio of interference can be substituted into a mathematical formula which then can be solved, errors of coupling between the interference signals and an object angle can be eliminated, and a real object angle can be estimated; the invention provides a simple and effective main lobe compound jamming resisting method which is easy to implement in the engineering field; the method disclosed in the invention can be applied to conventional object indication radar devices, tracking and guiding radar devices, terminal guiding radar devices and fire control radar devices and is of great practical significance.

The invention discloses a monitoring structure and a method of a single pulse radar system automatic self-checking and a condition parameter. The structure comprises a coupler, a digital attenuator and a single-tool two-board switch. The structure is joined in the single pulse radar system. A radar transmitter signal is formed in a self-checking signal by the coupler and the radar transmitter signal is fed back in a radar receiving passage. The self-checking signal or a transmitter leakage signal is received by a receiver under the coordination between a receiving processing time sequence and processing algorithm of different models, thus the self-checking, calibration, delicacy automatic survey and transmitter condition detection of a radar system passage are achieved. According to the monitoring structure and the method of the single pulse radar system automatic self-checking and the condition parameter, any periphery testing equipment is not needed to be added, thus the monitoring and survey of the calibration and the condition parameter of the single pulse radar system are achieved. The monitoring structure and the method of the single pulse radar system automatic self-checking and the condition parameter can be applied to an online testing system of the radar system widely.

A monopulse radar system aims to correct an amplitude error and a phase error developed between receiving channels and improve the accuracy of a detected angle. To achieve the above aim, part of a transmit signal is supplied to respective channels on the receiving side through a signal transmission line for calibration. At this time, the gains of a variable phase shifter and a variable gain amplifier are adjusted so that an azimuth angle of a pseudo target, based on a signal for calibration, which is calculated by signal processing means, reaches a predetermined angle. Therefore, calibration work is simplified and an angular correction can be automated. Therefore, the present monopulse radar system is capable of coping even with variations in characteristic after product shipment due to environmental variations and time variations in parts characteristic.

The method comprises: 1) designing a multiple antenna transmitting drive signal; 2) two dimensional modulation designing is made for said signal; 3) encoding the message to be transmitted; 4) the signal is modulated and transmitted; 5) making carrier extraction and coherent demodulation for the received signal. The invention not only has PSK and QPSK digital communication capacity, but also can make high accuracy direction finding like mono-pulse radar, and is a new architecture of bistatic radar or multistatic radar.

The invention belongs to the field of radar electronic countermeasure and discloses a single-pulse radar cross-eye interference detection method based on an auxiliary channel. Through angle measurement of one main channel and one auxiliary channel of the radar, when a single-pulse radar is subjected to cross-eye interference, whether cross-eye interference exists is detected through comparing theangle measurement results respectively obtained by the main channel and the auxiliary channel. The method is advantaged in that the method is mainly applied to early detection of cross-eye interference by the single-pulse radar, and then starts the corresponding technology to eliminate influence of interference on single-pulse direction finding performance, can be further applied to aircraft and various types of signal detection, identification and tracking devices, quickly identify cross-eye interference, improve system's interference identification capability and effectively combat cross-eyeinterference.

The invention relates to the technical field of radar signal processing and discloses an angle-measuring and identifying method for target and bait interferences in a main lobe of monopulse radar. The method comprises the following steps: with an improved radar receiver, extracting an echo signal of an opposite angle difference channel and judging if bait interference exists; with single target angle measurement and single pulse angle measurement for target and bait, identifying true and false target angles; and controlling an angle tracking gate of the monopulse radar according to the angle measurement output of a true target. According to the angle-measuring and identifying method provided by the invention, the receiver is used for extracting a double-difference signal and processing the signal, so as to realize the angle position estimation for two undistinguishable targets, complete bait interference detection and true target identification, increase the interference detection and identification accuracy and calculation efficiency and enhance the instantaneity of interference detection. The angle-measuring and identifying method provided by the invention has important practical significance in increasing the angle distinguishing capability of monopulse radar and improving existing target indication radar and tracking guidance radar and terminal guidance radar.