Patents
Literature
56 results about "Digital radio frequency memory" patented technology
Efficacy Topic
Property
Owner
Technical Advancement
Application Domain
Technology Topic
Technology Field Word
Patent Country/Region
Patent Type
Patent Status
Application Year
Inventor
Digital Radio Frequency Memory (DRFM) is an electronic method for digitally capturing and retransmitting RF signal. DRFMs are typically used in radar jamming, although applications in cellular communications are becoming more common.
Object indication radar object simulator
The invention discloses an object indication radar object simulator which is mainly applied to simulating radar reflection echoes of a missile type object and an airplane type object in a real state close to reality. The object indication radar object simulator comprises an emission antenna, an emission front end, a radiation pulse generation unit, a high precision reference source and C-wave band agility frequency source, a comprehensive control unit, a digital radio frequency memory unit, a receiving front end and a receiving antenna. Radar signals, after being converted down to an intermediate frequency through the receiving front end, penetrate into the radio frequency memory unit and are stored there, the comprehensive control unit performs control according to an object batch, a speed and distance information which are to be simulated, the radio frequency memory unit generates intermediate frequency signals of object echoes, then the radiation pulse generation unit and the emission front end simulate magnitude information and Doppler information of the echoes, and final, the emission antenna performs emission. The stimulator can simulate radar echo information of a real object and is mainly applied to dynamic object simulation, outfield test simulation, integrated practice and testing of a radar system.
Owner:CHANGCHUN UNIV OF SCI & TECH
Radar signal processing system based on DRFM (Digital Radio-Frequency Memory) technology and dense target jamming generation method
ActiveCN105629207ARealize control and management functionsNo added complexityWave based measurement systemsIntermediate frequencyRadar signal processing
The invention discloses a radar signal processing system based on DRFM (Digital Radio-Frequency Memory) technology and a dense target jamming generation method. A transmitting and receiving antenna receives a radar transmitting pulse, and an L-waveband microwave transmitting and receiving assembly carries out down conversion processing on a radar signal; a wideband digital radio frequency memory in a signal processing unit receives an intermediate frequency signal, and high-speed sampling and memory are carried out; an FPGA-based signal processor carries out piecewise superposition on the stored data, and an analog echo signal covering a radar detection distance range is generated; an all-digital single-sideband modulator carries out Doppler frequency shift on the echo signal; and an FPGA-based timing controller converts the echo signal through frequency shift into an intermediate frequency output signal. Delayed superposition forwarding increases the number and the density of false targets, dense target jamming approximate to noise can be realized, and functions of the DRFM, control and management and the like can be effectively realized.
Owner:NANJING UNIV OF SCI & TECH
Phase noise measurement system and method
ActiveUS8248297B1Extra delayEasy to useRadio wave reradiation/reflectionDigital radio frequency memoryFrequency mixer
System that measures absolute or additive phase noise includes a power divider for dividing an input RF signal, a local oscillator, two mixers, each arranged in a path of a respective signal component from the power divider and receiving input from the power divider and local oscillator, two digital radio frequency memories, each associated with a respective mixer and receiving an input signal therefrom, and a digital signal processor that receives signals from the digital radio frequency memories and outputs a digital data stream indicative of measured phase noise. For absolute phase noise measurement, phase noise of the input RF signal is provided. For additive phase noise measurement, a unit under test is arranged in one of the paths between the power divider and the mixer. The system may be interposed between a radar transmitter of a radar environment simulator and a radar receiver coupled to a radar target display.
Owner:ADVANCED TESTING TECH
Digital radio frequency memory based on analogue demodulation/modulation
InactiveCN103364765ASmall sizeImprove abilitiesWave based measurement systemsFrequency spectrumTarget signal
The invention discloses a digital radio frequency memory based on analogue demodulation / modulation. The digital radio frequency memory is provided with an FPGA (Field Programmable Gate Array), a FLASH, an RAM (Random Access Memory), A / Ds (Analog to Digital) and D / As (Digital to Analog) of a line I and a line Q, and a low pass filter, wherein the FLASH and the RAM are respectively connected with the FPGA through data lines; the A / D and the D / A of the line I and the line Q are respectively connected with the FPGA through data lines; the low pass filter is respectively connected with the D / As of the line I and the line Q. According to the digital radio frequency memory disclosed by the invention, the bandwidth which is better than 400MHz and the dynamic state which is better than 40dB are realized and the digital radio frequency memory can be applicable to radar signals of various systems; the digital radio frequency memory has the capability of improving the quality of a copying signal through using a sample screening technology and a sample frequency spectrum purification technology; a coherent interference signal can be generated through carrying out multi-pulse tracking and stable tracking on a target signal and an output signal can be subjected to normalization and peak-to-average ratio improvement treatment; the efficiency of interference is greatly improved and the digital radio frequency memory can be widely applied to various types of radar jammers.
Owner:AIR FORCE EARLY WARNING ACADEMY +1
Broadband linear frequency-modulated (LFM) signal multi-decoy interference method based on fractional Fourier domain channelization
InactiveCN103532656AIntegrity guaranteedReduce instantaneous bandwidth requirementsCommunication jammingBroadbandEngineering
The invention relates to a broadband linear frequency-modulated (LFM) signal multi-decoy interference method based on fractional Fourier domain channelization, in particular to an interference method for performing multi-decoy deception on a broadband LFM signal in a pulse on the basis of fractional Fourier domain channelization, and belongs to the technical field of electronic interference. According to the broadband LFM signal multi-decoy interference method based on fractional Fourier domain channelization, all broadband LFM signals can be focused into one channel for outputting by using the energy focusing property of fractional Fourier transform on instable signals, so that the completeness of the signals is ensured, and the problems of reduction of signal energy and distortion of waveforms since the energy of the broadband LFM signals overflow into two or more channels in the conventional Fourier domain channelization are solved; meanwhile, the requirement on the instant bandwidth of a DRFM (Digital Radio Frequency Memory) system is lowered.
Owner:BEIJING INSTITUTE OF TECHNOLOGYGY
Radar target echo simulation system based on electromagnetic scattering model, and simulation method thereof
ActiveCN109239684AIncrease credibilitySolve the problem that the target echo simulation is not realisticWave based measurement systemsFourier transform on finite groupsElectromagnetic field
The invention discloses a radar target echo simulation system based on an electromagnetic scattering model, and a simulation method thereof. The simulation method comprises the following steps: utilizing electromagnetic field simulation software, taking a precise three-dimensional geometric model of the radar target as input, setting radar frequency, space angle and like parameters, and computingradar target electromagnetic scattering characteristics through offline simulation; generating target electromagnetic scattering characteristic data under different frequencies and different space angles, and forming a scattering model database; when performing the radar target echo simulation, preloading the target electromagnetic scattering characteristic data to a simulator digital radio frequency memory unit (DRFM) according to the frequency and the orbit information of the radar test, wherein the DRFM performs real-time transmission on the target electromagnetic characteristic data underthe simulation frequency and the current simulation attitude through a table look-up way, and a signal processing unit controls the DRFM to accomplish frequency domain convolution of a radar emissionsignal and the target scattering characteristic data, and performs inverse Fourier transform processing on a convolution result to obtain a target time domain echo.
Owner:NO 8511 RES INST OF CASIC
Two-channel digital radio-frequency memory board
InactiveCN101604541AHigh frequencyEasy to storeData switching by path configurationDigital recording/reproducingData acquisitionData memory
The invention relates to a two-channel digital radio-frequency memory board, and belongs to the technical field of data memory. The two-channel digital radio-frequency memory board comprises a power module, an ADC data acquisition module, a DAC data playback module, a DDR2 memory module, an FPGA acquisition control module, an FPGA playback control module, a DSP communication control module, an analog signal input interface module, an analog signal output interface module, a PCI interface module, a Rapid IO interface module and a customized bus interface module. The two-channel digital radio-frequency memory board is provided with two signal acquisition processing playback circuit branches, and each circuit branch has the sampling rate of 1.2GSPS and the playback rate of 1.2GSPS; and the two-channel digital radio-frequency memory board has various signal acquisition processing playback modes and data transmission mode, can realize functions of memorizing and forwarding signals with high frequency, and is suitable to be applied to the field of radar and electronic warfare confrontation.
Owner:BEIJING INSTITUTE OF TECHNOLOGYGY
General radio altitude simulator based on DRFM
InactiveCN103245936AWave based measurement systemsRadio wave reradiation/reflectionConvolution filterRadio frequency signal
The invention discloses a realization method of a missile radio altimeter height signal simulator based on DRFM (Digital Radio Frequency Memory) technology. The method applies the DRFM technology to the radio altimeter signal simulating since the DRFM technology can retain the subtle features of the radio frequency signal. According to the method provided by the invention, continuous sampling cycle storage technology, address register cycle reset and pulse delay precision control technology are adopted, and as the method is based on DRFM system digital noise modulation technology and digital convolution filter technology, a series of technical problems of applying the DRFM technology to the altimeter signal environment are solved, highly numerical simulation precision control and continuous adjustable are realized and a plurality of interference signals of the radio altimeter can be simulated. And as the method is under use in a certain testing system developed in our institution, the effectiveness and the validity of the method is tested and verified.
Owner:NAVAL AERONAUTICAL & ASTRONAUTICAL UNIV PLA
Linear frequency modulation continuous wave system based on chaotic coding frequency agility and application method thereof
InactiveCN108776329AStrong ability to cooperateExcellent distance resolutionWave based measurement systemsIntermediate frequencySelf correlation
Owner:NANJING UNIV OF SCI & TECH
Programmable transmitter and receiver including digital radio frequency memory
InactiveUS7116242B2Reduced board areaFast programmingElectric signal transmission systemsMultiple keys/algorithms usageRadio frequencyDigital radio frequency memory
A vehicular programmable transceiver includes a digital radio frequency memory (DRFM) having at least one register configured to sample and hold a radio frequency input signal in response to a clock signal and to generate an output signal having a carrier frequency generated in response to the sampled and held input signal.
Owner:LEAR CORP
Active camouflage protection method and device based on multiple phase sectionalized modulation radar interference
ActiveCN106646398AReduce sizeRealize the purpose of camouflage protectionRadio wave reradiation/reflectionBackground imageComputer science
The invention discloses an active camouflage protection method and device based on multiple phase sectionalized modulation radar interference. According to the invention, image blocks with the number, the position, the area and the brightness being controllable are generated on a synthetic aperture radar image to cover a target image and peripheral background image through controlling characteristics of an interference signal so as to achieve a camouflage purpose. The method disclosed by the invention is processing performed on two dimensions; received signals are uniformly-spaced pulse signals; when the maximum length of subsection signals is less than the pulse width of the received signals, the subsection is a short subsection which is interference for the distance dimension; and when the minimum length of the subsection signals is greater than a pulse repetition period of the received signals, the subsection is a long subsection which is interference for the Doppler dimension. The active camouflage protection device comprises a controller and a digital radio frequency memory DRFM, wherein the controller and the digital radio frequency memory DRFM are connected in series, and the controller controls a sectionalizing mode and a modulation phase value of radar signals; and the DRFM acquires one-dimensional interference signals and two-dimensional interference signals according to the sectionalizing mode and the modulation phase value.
Owner:PLA PEOPLES LIBERATION ARMY OF CHINA STRATEGIC SUPPORT FORCE AEROSPACE ENG UNIV
Digital radio frequency memory
InactiveUS20080266152A1Analogue/digital conversionMultiple-port networksDigital signal processingTime delays
A digital radio frequency memory (DFRM) which converts an incoming analog radio frequency signal to a fourteen bit digital signal allowing for digital signal processing and then retransmitted as an analog RF signal. The DFRM provides a time delay for RF signals by storing the signal. The DFRM also changes the signal frequency in the range of plus or minus 100,000 KHz which places a doppler on the signal. The signal phase is changed in a range of 0 to 359 degrees by the DFRM.
Owner:THE GOVERNMENT OF THE UNITED STATES OF AMERICA AS REPRESENTED BY THE SEC OF THE NAVY NAVAL RES LAB WASHINGTON
Simultaneous communications jamming and enabling on a same frequency band
InactiveUS20130315341A1Mitigate and even benefit from effectFacilitate communicationSecret communicationCommunication jammingCombined useFull band
There is described the use of Digital Radio Frequency Memory (DRFM) modules to jam certain communication signals while allowing others to be received on a given frequency band. The DRFM modules exploit the multi-path phenomenon by using transmitted signals to cause full band destructive echoes and / or distortions. A set of receivers used in conjunction with the DRFM modules are aware of the exact multi-path induced by the DRFM modules and are therefore able to mitigate or even benefit from the effects of the destructive multi-path and maintain or improve communications.
Owner:ULTRA ELECTRONICS TCS
Radar signal emission method for resisting radio frequency storage forwarding interference
ActiveCN105572643AEasy to identifyIncrease the difficultyWave based measurement systemsStore and forwardBroadband
The invention discloses a radar signal emission method for resisting radio frequency storage forwarding interference, which utilizes the digit radio frequency storage forwarding work principle and combines with the bandwidth advantage of the radar broadband signal work. The radar emits the broadband signal, which covers a plurality of digital channelization investigation channels of a jammer, increases the accuracy recognition and jamming difficulty of the jammer on the radar signal through actively optimizing the signal waveform in the broadband, causes the fact that the jammer only interferes parts of the frequency part and reduces the adverse affect brought by the jammer. The radar on a reception terminal firstly performs spectral analysis on the received radar echo to determine whether the radar receives the radio frequency storage forwarding interference, if the radar is found to be interfered, the removal of the interference frequency band can be performed during the pulse pressure, and the signal of the rest part which is not interfered is utilized to perform the object detection.
Owner:HOHAI UNIV
DRFM (digital radio frequency memory)-based jamming signal generation method for radio altimeter
ActiveCN103727960AWave based measurement systemsRadio wave reradiation/reflectionAnti jammingConvolution filter
The invention discloses a DRFM (digital radio frequency memory)-based jamming signal generation method for a radio altimeter. The method comprises the following steps of generating a range deception jamming signal for the altimeter according to the DRFM-based data circulating storage and read-write signal delay accurate-control technology; generating a radio frequency noise jamming signal for the altimeter according to the DRFM-based digital noise modulation technology; generating a false target jamming signal for the altimeter according to the DRFM-based data circulating storage and digital convolution filter technology; generating a range-speed synchronous jamming signal for the altimeter according to the DRFM-based frequency-shifting jamming technology. According to the method, the generated jamming signals for the altimeter are integrated to meet the requirements of anti-jamming performance tests of the radio altimeter of an anti-ship missile; the technology is applied to a universal radio altitude simulation device developed by the Naval Aeronautical Engineering Academy to finish testing two types of radio altimeters and verify the accuracy of the method; the radio altimeter jamming signals are applied to a missile-borne radio altimeter, and can also be popularized to an airborne radio altimeter.
Owner:NAVAL AVIATION UNIV
Multi-radar interference inhibition method for preventing interference in digital radio frequency storing and forwarding
ActiveCN105388464AEliminate distractionsInterference reservationWave based measurement systemsRadio frequencyMain lobe
The invention discloses a multi-radar interference inhibition method for preventing interference in digital radio frequency storing and forwarding. The method comprises the following steps: firstly, two pieces of radar receiving radar echo data; secondly, conducting interaction on the data of the radar to enable the data of the two pieces of radar to be synchronous; thirdly, aligning the integrated echo interference data of the two pieces of radar in sequence, and then performing interference cancellation processing based on the minimum mean squared error, the least square or the like; fourthly, providing trace points exceeding a detection threshold after the two pieces of radar conduct pulse voltage matching and constant false-alarm rate (CFAR) processing on the radar interference echo data after interference cancellation of the data; and fifthly, fusing the trace points of the two pieces of radar, and providing a target track. According to the multi-radar interference inhibition method, two radar platforms coordinate with each other through a network, and after received data of two pieces of radar is aligned sequentially, false interference of digital radio frequency storing and forwarding received by radar main lobes is prevented by means of the isotropy characteristics of digital radio frequency storing and forwarding interference signals, the non-isotropy characteristics of target echo signals as well as amplitude differences between signals and interference.
Owner:HOHAI UNIV
Digital Radio Frequency Memory
InactiveUS20080268806A1Multiple-port networksWave based measurement systemsDigital signal processingTime delays
A digital radio frequency memory (DFRM) which converts an incoming analog radio frequency signal to a fourteen bit digital signal allowing for digital signal processing and then retransmitted as an analog RF signal. The DFRM provides a time delay for RF signals by storing the signal. The DFRM also changes the signal frequency in the range of plus or minus 100,000 KHz which places a doppler on the signal. The signal phase is changed in a range of 0 to 359 degrees by the DFRM.
Owner:NAVY U S OF A AS REPRESENTED BY THE SEC OF
Two GHz bandwidth digital radio frequency memorizer and storage method
InactiveCN103902482AMeet the needs of development in the field of RF simulationMeet development needsElectric digital data processingDigital conversionDigital radio frequency memory
The invention discloses a two GHz bandwidth digital radio frequency memorizer and a storage method. The memorizer comprises a broadband analog / digital converter (ADC), a radio frequency processing field-programmable gate array (FPGA) and a storage pool. The radio frequency FPGA comprises a serial / parallel converting unit. The ADC is connected with the input end of the serial / parallel converting unit, and the output end of the serial / parallel converting unit is connected with the storage pool. The two GHz bandwidth digital radio frequency memorizer and the storage method are mainly used in the technical field of radar radio frequency emulation and have the capability of collecting and playing back high-speed data, the functions of data collecting, storing, transmitting, playing back and the like can be achieved flexibly, the problem that an existing DRFM system bandwidth is not enough can be solved, and the capability and speed of radio frequency signal storing are improved.
Owner:北京华清瑞达科技有限公司
Digital radio frequency memory board
The invention provides a digital radio frequency memory board. An analog / digital converter module for the digital radio frequency memory board is used for acquiring an external analog signal at a high speed, converting the external analog signal into a digital signal and transmitting the digital signal to a first field programmable gate array (FPGA) module, wherein the first FPGA module is used for performing primary programmable processing on the digital signal and transmitting the digital signal to a second FPGA module; the second FPGA module is used for performing secondary programmable processing on data and finally transmitting the data to a digital / analog converter module; the digital / analog converter module is used for converting the digital signal into an analog signal at a high speed and outputting the analog signal; a first static random access memory (SRAM) module is connected with the first FPGA module and is used for caching data of the first FPGA module; and a second SRAM module is connected with the second FPGA module and is used for caching data of the second FPGA module. The digital radio frequency memory board has high-speed data acquisition and playback capacity, and the functions of data acquisition, storage, transmission and playback can be flexibly realized.
Owner:BEIJING JINGWEI HIRAIN TECH CO INC
Inter-pulse initial phase third-power modulation and FRFT (fractional Fourier transform)-based DRFM (digital radio frequency memory) interference detection and resisting method
ActiveCN106019243AEasy to follow upDetection of goals achievedWave based measurement systemsPower modulationSignal-to-noise ratio (imaging)
The invention discloses an inter-pulse initial phase third-power modulation and FRFT (fractional Fourier transform)-based DRFM (digital radio frequency memory) interference detection and resisting method. According to the method, a multi-channel matched filter and MTD (moving target detection) are utilized to detect whether interference exists, and if interference exists, the priori information of the interference and a target are utilized to design the initial phase of the transmission pulses of a radar, the transmission pulses of the radar are transmitted; matched filtering processing of corresponding channels is carried out on echoes; and FRFT (fractional Fourier transform) is utilized to suppress the interference. With the method of the invention adopted, the detection of the target can be realized under a low signal-to-interference ratio; the signal-to-interference ratio can be improved greatly under the premise that a signal-to-noise ratio is not affected, so that the subsequent processing of signals can be facilitated; and with the decrease of the signal-to-interference ratio, the interference suppression performance of the method is stable.
Owner:NANJING UNIV OF SCI & TECH
Intermittent sampling and forwarding interference in multicarrier phase coding radar signals
The invention discloses intermittent sampling and forwarding interference in multicarrier phase coding radar signals; and the invention introduces intermittent sampling and forwarding interference toa multicarrier phase coding system radar, and is an intermittent sampling based multicarrier phase coding interference method. The method utilizes a digital radio frequency memory to perform periodicintermittent under-sampling processing on a target radar signal, and performs forwarding on a sampling signal by setting a forwarding pattern. The method specifically includes the following steps: 1)generating signals; 2) estimating interference parameters; 3) performing intermittent sampling processing on an interception signal; and 4) performing forwarding on interference according to the set forwarding pattern. The method makes up disadvantages of conventional interference of being simple in form, low in complexity and high in predictability; and controllable vivid false target interference in the amplitude, quantity and spatial distribution of the multicarrier phase coding radar can be realized by reasonably setting the interference parameters.
Owner:CHANGSHA UNIVERSITY OF SCIENCE AND TECHNOLOGY
Projectile echo simulating device and method for emplacement reconnaissance and fire-directing radar
ActiveCN110412528AEasy to operateReduce difficultyCosmonautic condition simulationsWave based measurement systemsMicrowaveRadar
The invention relates to the technical field of target simulating, and discloses a projectile echo simulating device and method for an emplacement reconnaissance and fire-directing radar. The simulating device comprises a lifting device, a transverse moving device, a servo and synchronous control device, a digital radio frequency memory microwave delay circuit, a transceiving antenna and a microwave cable. The transverse moving device is horizontally arranged at the upper portion of the lifting device. The transceiving antenna is installed on the transverse moving device and can horizontally move under the control of the transverse moving device. The digital radio frequency memory microwave delay circuit is connected with the transceiving antenna through the microwave cable. The lifting device, the transverse moving device and the digital radio frequency memory microwave delay circuit are connected with the servo and synchronous control device through signals. By means of the projectile echo simulating device and method for the emplacement reconnaissance and fire-directing radar, the problem is solved that the emplacement reconnaissance and fire-directing radar is difficult to train and organize and high in training cost, and meanwhile the problem is solved that projectile trajectory echoes simulated by a simulating device in an existing emplacement reconnaissance and fire-directing radar are unreal.
Owner:XIAN UNIV OF POSTS & TELECOMM
Respond wireless interference signal generator and method thereof
The invention discloses a respond wireless interference signal generator and a method thereof. According to the device, a PDA (personal digital assistant) connected with a DSP (digital signal processing) controller is connected with a programmable pulse time delay circuit, a frequency synthesizer and a DDS (direct digital synthesizer) respectively; the frequency synthesizer outputs a local oscillator signal to the DDS and a signal receiving circuit; a time delay circuit is connected with the control end of a DFRM (digital radio frequency memory) of which the input end is connected with a receiving circuit and an antenna; the output end of the DFRM is connected with an IF (intermediate frequency) mixer connected with a clutter generator by a numerical control attenuator; the output end of the IF mixer is connected with a plurality of signal output circuits by a power distributor; and each signal output circuit is also connected with the DDS, and the tail end of each path of output circuit outputs a modulated simulation target signal through the antenna. The respond wireless interference signal generator and the method thereof can perform programming process according to an aerial target motion rule, performs deception or checking on radio positioning equipment by the directed radiation of received same frequency and signal modes, and are suitable for various kinds of radio positioning equipment.
Owner:廖华芬 +1
Two-dimensional smart noise interference method based on centralized MIMO radar
The invention discloses a two-dimensional smart noise interference method based on a centralized MIMO radar, and belongs to the technical field of radar communication.The method comprises the steps that down-conversion processing is carried out on radar transmitting signals intercepted by a digital radio frequency memory through a jammer, and the radar transmitting signals are subjected to down-conversion processing; periodic sampling is carried out on each pulse of a signal transmitted by an enemy through intermittent sampling to form a plurality of slices, then smart noise interference modulation is carried out in a distance dimension and a speed dimension, and finally, up-conversion processing is carried out on a modulation signal, so that a forwarding type two-dimensional smart noise interference signal is formed. After an MIMO radar receives an interference signal, a result obtained by a conventional signal processing method is seriously influenced by the interference signal generated in the invention. According to the method, smart noise interference is applied to an enemy radar signal in the distance dimension and the speed dimension, and an intensive false target is successfully generated, so that the detection of the MIMO radar on a real target is interfered.
Owner:NANJING UNIV OF SCI & TECH
Interference machine for resisting pulse Doppler radar and interference method thereof
The invention provides a jammer for resisting a pulse Doppler radar and a jamming method of the jammer and belongs to the technical field of electronic countermeasures. The jammer comprises a receiving antenna, a receiving front end, a coupler, a receiving channel, a digital radio frequency memory, a transmitting channel, a digital control attenuator, a power amplifier, a transmitting antenna, a single-bit receiver, an interference controller, a DDS signal generator, an interference controller and a local oscillator. According to the jammer, a broad pulse coverage jamming method is carried out on a pulse Doppler radar under a low repetition frequency characteristic, a Doppler false target jamming method is carried out on a pulse Doppler radar under a medium-high repetition frequency characteristic, jamming signals and radar signals are coherent, coherent processing gains of the radar signals can be obtained, the jammer has the characteristics of high interference efficiency, good interference effectiveness and the like.
Owner:NANJING INST OF TECH +1
Signal synthesizer and method therefor
InactiveUS7154431B2Increase in sizeSmall sizeMultiple-port networksDelay line applicationsSoftware engineeringRadio frequency
A digital synthesizer includes a digital radio frequency memory (DRFM) for storing phase values and corresponding digital signals. The digital synthesizer includes a digital processing circuit receiving input from the DRFM, the circuit including tapped delay lines and a summer summing the output of the tapped delay lines. The digital synthesizer includes a signal modulator independently synthesizing within each tapped delay line a frequency modulated and gain scaled signal, wherein input to the tapped delay lines are phase values from the DRFM.
Owner:THE UNITED STATES OF AMERICA AS REPRESENTED BY THE SECRETARY OF THE NAVY
Radar echo delay coherent simulation method based on digital radio frequency memory
ActiveCN107346018AIncrease flexibilityHigh precisionWave based measurement systemsIntermediate frequencyDigital radio
The invention provides a radar echo delay coherent simulation method based on a digital radio frequency memory, which includes the following steps: S1, a simulator extracts the envelope of radar transmitted signal pulses, and uses a local clock to perform clock counting N3 in N2 radar transmitted pulse cycles; S2, the echo delay analog quantity tau'(n) after correction is calculated; S3, the nominal clock cycle number k' of the corresponding simulator is calculated according to the echo delay analog quantity tau'(n); and S4, the readout sequence of digital medium-frequency signals obtained after processing by the simulator and saved in a digital radio-frequency form is controlled using the k' value, thus completing radar echo delay simulation. Through the method, coherent simulation of radar echo delay can be completed quickly.
Owner:BEIJING INSTITUTE OF TECHNOLOGYGY
Digital radio frequency memory
InactiveUS7792218B2Multiple-port networksWave based measurement systemsDigital signal processingRadio frequency signal
A digital radio frequency memory (DFRM) which converts an incoming analog radio frequency signal to a fourteen bit digital signal allowing for digital signal processing and then retransmitted as an analog RF signal. The DFRM provides a time delay for RF signals by storing the signal. The DFRM also changes the signal frequency in the range of plus or minus 100,000 KHz which places a doppler on the signal. The signal phase is changed in a range of 0 to 359 degrees by the DFRM.
Owner:NAVY U S OF A AS REPRESENTED BY THE SEC OF
Radar Target Echo Simulation System and Simulation Method Based on Electromagnetic Scattering Model
ActiveCN109239684BIncrease credibilitySolve the problem that the target echo simulation is not realisticWave based measurement systemsEngineeringReal time transmission
The invention discloses a radar target echo simulation system based on an electromagnetic scattering model, and a simulation method thereof. The simulation method comprises the following steps: utilizing electromagnetic field simulation software, taking a precise three-dimensional geometric model of the radar target as input, setting radar frequency, space angle and like parameters, and computingradar target electromagnetic scattering characteristics through offline simulation; generating target electromagnetic scattering characteristic data under different frequencies and different space angles, and forming a scattering model database; when performing the radar target echo simulation, preloading the target electromagnetic scattering characteristic data to a simulator digital radio frequency memory unit (DRFM) according to the frequency and the orbit information of the radar test, wherein the DRFM performs real-time transmission on the target electromagnetic characteristic data underthe simulation frequency and the current simulation attitude through a table look-up way, and a signal processing unit controls the DRFM to accomplish frequency domain convolution of a radar emissionsignal and the target scattering characteristic data, and performs inverse Fourier transform processing on a convolution result to obtain a target time domain echo.
Owner:NO 8511 RES INST OF CASIC
A Radar Signal Transmission Method Against Radio Frequency Store-and-Forward Interference
ActiveCN105572643BEasy to identifyIncrease the difficultyWave based measurement systemsStore and forwardBroadband
The invention discloses a radar signal emission method for resisting radio frequency storage forwarding interference, which utilizes the digit radio frequency storage forwarding work principle and combines with the bandwidth advantage of the radar broadband signal work. The radar emits the broadband signal, which covers a plurality of digital channelization investigation channels of a jammer, increases the accuracy recognition and jamming difficulty of the jammer on the radar signal through actively optimizing the signal waveform in the broadband, causes the fact that the jammer only interferes parts of the frequency part and reduces the adverse affect brought by the jammer. The radar on a reception terminal firstly performs spectral analysis on the received radar echo to determine whether the radar receives the radio frequency storage forwarding interference, if the radar is found to be interfered, the removal of the interference frequency band can be performed during the pulse pressure, and the signal of the rest part which is not interfered is utilized to perform the object detection.
Owner:HOHAI UNIV