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65 results about "Instantaneous frequency measurement" patented technology

Pure phase type broad frequency band microwave radiation source direction finding system and method

InactiveCN101105525AFast and accurate direction findingSimple structureDirection findersIntermediate frequencyFindings methods
The invention provides a pure phase type broadband microwave radiation source direction-finding device and a direction-finding method; the pure-phase type broadband microwave radiation source direction-finding device comprises a digital receiver, an instantaneous frequency measurement receiver and a signal processor; wherein each passage of the digital receiver consists of an antenna, a filter, a frequency mixer and an intermediate frequency amplifier; the intermediate frequency amplifier is connected with the digital receiver; microwave signals which are generated by local oscillator source connected with the signal processor and has fixing frequency difference with incident signal frequency and output signals of the filter are input into the frequency mixer, and intermediate frequency signals with fixing frequency are obtained. Based on phase position interferometer direction finding, the microwave radiation source direction-finding method adopting pure phase utilizes the phase position difference between long base line and short base line, establishes virtual short base line, implements ambiguity resolution by combining physical reliable long base line and short base line, resolves the contradiction between the covering bandwidth of the phase position interferometer and the angle-finding range of the phase position interferometer, and can realize rapid accurate direction finding of space microwave radiation source in broadband only by the utilization of phase position information.
Owner:HARBIN ENG UNIV

High-precision digital instantaneous frequency measurement method and device

InactiveCN103837740ASolve the problem of low frequency measurement accuracyReduce data flow rateFrequency measurement arrangementDigital signal processingIntermediate frequency
The invention discloses a high-precision digital instantaneous frequency measurement method and device. The method comprises the steps that frequency conversion and filtering of radio-frequency signals are carried out at the radio-frequency receiving front end, and X-waveband signals are converted to be medium-frequency signals; AD conversion is carried out on the medium-frequency signals, down-conversion is carried out on the converted medium-frequency signals through a digital signal processing device, and then medium-frequency digital signals are obtained; the medium-frequency digital signals are converted to be base-band digital signals; a dual-signal estimation method based on an FFT and signal square is adopted, the base-band digital signals are computed through an FPGA, and a frequency measurement result is obtained. The high-precision digital instantaneous frequency measurement method and device solve the problem that the frequency measurement precision of the X-waveband pulse signals is not high in the prior art. The dual-signal estimation method based on the FFT and signal square is adopted, after the relative rapidness of the FFT frequency measurement algorithm and the one-dimensional square signal spectrum peak search are combined, the accuracy of frequency intervals is estimated through interpolation, and as the FPGA hardware is utilized for achieving related algorithm, the rapidness and accuracy of frequency measurement are ensured.
Owner:BEIJING AEROSPACE MEASUREMENT & CONTROL TECH

Multi-frequency microwave signal photon instantaneous frequency measuring device with super-wide frequency range

InactiveCN103439011AIncreased frequency measurement rangeLow costInstrumentsFrequency measurementsPhoton
The invention discloses a multi-frequency microwave signal photon instantaneous frequency measuring device with a super-wide frequency range, and belongs to the technical field of microwave photonics. The multi-frequency microwave signal photon instantaneous frequency measuring device with the super-wide frequency range comprises a laser, a coupler, a phase modulator, a polarization controller, a highly nonlinear optical fiber, a circulator, a first double-parallel MZ modulator, a second double-parallel MZ modulator, an intensity modulator, a microwave coupler, a photoelectric detector and a network analysis instrument. First-order upper side band signals output by the phase modulator are strengthened or weakened through the stimulated Brillouin scattering effect of the highly nonlinear optical fiber, the intensity balance of the first-order upper side band and the first-order lower side band of the output signals of the phase modulator is broken, and therefore instantaneous frequency measurement of multi-frequency microwave signals to be measured is achieved.
Owner:JILIN UNIV

Device and method for realizing instantaneous frequency measurement using phase modulator

ActiveCN106656322AChange angleDetermine the frequency valueElectromagnetic transmissionObservational errorPolarizer
The invention discloses a device and a method for realizing instantaneous frequency measurement using a lithium niobate phase modulator. The device and the method relate to the technical field of microwave and the technical field of optical communication, and are mainly applied to the field of electronic reconnaissance. The device comprises a laser, a polarization controller, a phase modulator, a standard single-mode optical fiber, an optical divider, a polarizer and an optical receiver, as shown in the appended drawings. By using the polarization sensitive property of the lithium niobate phase modulator and reasonably adjusting the polarization controller, phase modulation and intensity modulation can be realized at the same time. Based on the dispersion characteristic of the optical fiber, two frequency response functions opposite in change trend can be constructed. Thus, an amplitude comparison function obtained changes more quickly in a large band. By calculating the power ratio of upper and lower branches, the frequency of a to-be-measured microwave signal can be estimated. The measurement error of the device within the range from 1.6GHz to 24.6GHz is less than + / -0.3GHz.
Owner:XIDIAN UNIV

Instantaneous frequency measurement method based on adaptive filtration theory

The invention discloses an instantaneous frequency measurement method based on the adaptive filtration theory. The adaptive filtering algorithm is utilized to decompose a nonstationary multi-frequency component signal into a plurality of progressive single-frequency signals to be measured, thus solving the analyzing problem of the multi-frequency component signal. The Hilbert transformation is adopted to perform instantaneous frequency measurement to the progressive single-frequency signals, thus complete and accurate instantaneous physical quantity of the nonstationary multi-frequency component signal can be obtained, the time-frequency distribution of the nonstationary signal can be further obtained and the requirements of instantaneous frequency measurement in the fields of military communication and electronic countermeasure can be satisfied.
Owner:XIDIAN UNIV

Method and apparatus for real time measurement of three phase electrical parameters

An apparatus and method for determining, in real time, the key parameters of a three phase system electrical generator's output. A pair of reference vectors in quadrature (orthogonal) is phase-locked to a selected input open delta line to line voltage vector. Preferably, the cosine reference vector is locked 45 DEG out of phase from the selected input vector whereby a best projection of the input vector onto the quadrature pair is provided and increases accuracy in subsequent magnitude and phase calculations. The phase-locked reference vectors provide a basis for computing the magnitude and phase angle for the remaining open delta line to line voltage vectors and three line to neutral current vectors. Instantaneous measurement of magnitude and phase angle for the three line to line voltages and three line to neutral currents, the generator's real power (watts), volt-amperes reactive (VARS), apparent power (VA), power factor (PF) and, as a result of the phase locking, the precise frequency of the generator are possible.
Owner:GENERAL ELECTRIC CO

Instantaneous frequency measuring method and system

ActiveCN105812053AMeet the measurement rangeMeet the measurement accuracy requirementsElectromagnetic transmissionIntensity modulationMeasurement precision
The invention provides an instantaneous frequency measuring method and system. The method includes that a polarization modulator performs polarization modulation on to-be-detected microwave signals and a first adjustable light source as well as a second adjustable light source; a polarization beam splitter divides the to-be-detected microwave signals to first branch optical signals and second branch optical signals; a first polarization controller and a first analyzer perform phase modulation on the first branch optical signals; a second polarization controller and a second analyzer performs intensity modulation on the second branch optical signals. A dispersion element is utilized for performing dispersion attenuation on the two branch optical signals. A first photoelectric detector converts the first branch optical signals subjected to dispersion attenuation to first branch electric signals. A second photoelectric detector converts the second branch optical signals subjected to dispersion attenuation to second branch electric signals. A digital processing unit obtains the instantaneous frequency of the to-be-detected microwave signals according to the input signals of the photoelectric detectors. The method and system provided by the invention can meet requirements for measurement range and measurement precision in instantaneous frequency measurement.
Owner:BEIJING UNIV OF POSTS & TELECOMM

Digital down converter-Hilbert-Huang transform based instantaneous frequency measuring method

The invention relates to a digital down converter-Hilbert-Huang transform based instantaneous frequency measuring method, applied to the technical filed of radio. The method includes the following steps: 1) an original signal is subject to digital down conversion, and interested signal is converted into zero intermediate frequency; 2) the converted signal is subject to Huang transform, thus obtaining all the single frequency components; 3) each single frequency component signal is subject to Hilbert transform, and instantaneous frequency of the converted signal is solved; 4) the instantaneous frequency of the original signal is recovered according to the instantaneous frequency of the converted signal finally. The invention not only can show the advantage that the traditional Hilbert-Huang transform (HHT) can realize linearization and stabilization of non-linear and non-stationary signal, but also well overcomes frequency aliasing of the traditional HHT transform and shows higher frequency resolution. The invention is verified in a designed hardware system, and the algorithm can carry out effectively real-time estimation on frequency.
Owner:XIDIAN UNIV

Signal parameter real-time precision measurement method of synthetic aperture radar

The invention provides a signal parameter real-time precision measurement method of a synthetic aperture radar (SAR) and belongs to the field of radar signal detection. The method integrates the digital channelized receiver technique and the phase difference instantaneous frequency measurement technique to achieve the real-time parameter measurement of the signals of the SAR; in consideration of the processing capacity of the processor and the hardware resources, the parallel processing method and the hardware resource time division multiplexing method are integrated to achieve the real-time processing of the huge data stream generated by the signals of the high-bandwidth high-timewidth non-cooperative SAR in the prior processor; the inherent error of the system time parameter is analyzed by use of the laboratory environment and the time parameter is compensated; and the transient response is avoided by utilizing the characteristics of the SAR signals and the frequency-domain parameter is correctd to obtain the accurate frequency-domain parameter. The method reduces the computation load, provides full consideration, achieves the real-time precision measurement of the signal parameters of the high-bandwidth high-timewidth non-cooperative SAR, and improves the real-time property and the precision of processing the high-bandwidth high-timewidth signals of the detection receivers in service.
Owner:BEIJING INSTITUTE OF TECHNOLOGYGY

Photon instantaneous frequency measurement scheme with broadband measurement range

The invention discloses a photon instantaneous frequency measurement scheme with a broadband measurement range. Microwave signals are loaded to three continuous laser light sources with different output wavelengths through a carrier-suppressed single sideband modulating module; and only +1-order (or -1-order) light sidebands are generated. The three +1-order (or -1-order) light sidebands are divided into two paths and are input into two phase demodulation modules respectively. A first phase demodulation module adopts a first laser wavelength and a second laser wavelength while the second phase demodulation module adopts the first laser wavelength and a third laser wavelength so as to obtain two phase values of which the change periods are mutually in a prime number relation in a frequencydomain. A unique determined microwave frequency can be demodulated in a frequency interval (F=F1*F2) according to the two phase values which are mutually in the prime number relation. By using the scheme of the invention, a frequency measurement range is manyfold expanded on the premise of not changing frequency measurement accuracy.
Owner:SOUTHWEST JIAOTONG UNIV

Large-dynamic ultra-wideband digital instantaneous frequency measurement method

InactiveCN108011677AIncrease probability of interceptImprove frequency resolutionTransmission monitoringUltra-widebandNoise (radio)
The invention discloses a large-dynamic ultra-wideband digital instantaneous frequency measurement method. The method adopts a radio frequency division technology and is combined with a channelized digital frequency measurement method, so that the covered frequency band is wide, the interception probability is high, and the high frequency resolution can be kept. The method selects 32 paths of digital channelization, so that the frequency measurement delay is ensured not to exceed 1 microsecond and the frequency measurement precision is within the range of 1 MHz. A radio frequency division module carries out three-stage amplification and equalization on an input 1-18 GHz radio frequency signal firstly, so that the input amplitude dynamic range is compressed through the design, and the dynamic range of the input signal is -45 dBm to 0 dBm, and the dynamic range is compressed to -5 dBm to 0 dBm after multi-stage amplification and equalization; and meanwhile, the deterioration of a signal-to-noise ratio is reduced; and furthermore, the amplitude flatness of 1 to 18 GHz of an ultra-wideband signal is ensured, so that the power of full-band signals sent to a frequency divider is within the normal working range of the frequency divider.
Owner:NANJING CHANGFENG AEROSPACE ELECTRONICS SCI & TECH

Instantaneous frequency measurement method and system with adjustable measurement range based on polarization modulator

The invention provides an instantaneous frequency measurement method and system with an adjustable measurement range based on a polarization modulator, and relates to the field of microwave photonics.In the system, TE and TM modes of light waves are subjected to constant-amplitude reverse-phase modulation through a light polarization modulator, and relative phase shift is introduced between the TE and TM modes through bias voltage; combining TE mode light waves and TM mode light waves through an optical power divider shunt and a polarizing film; further introducing equivalent dispersion intoupper and lower paths through a dispersion module formed by optical fibers; mapping the frequency information of a to-be-measured signal to phase information caused by dispersion, carrying out the photoelectric conversion through PD, transferring the frequency information to the amplitude of a photocurrent alternating current component, constructing an amplitude comparison function ACF through thealternating current component in a photocircuit, and calculating the frequency of the to-be-measured signal through the ACF function. The system is simple in structure, the measurement range of the system can be changed by adjusting the bias voltage and the polarization angle of the lower branch, and the measurement resolution of the system can be improved by optimizing the slope of the ACF.
Owner:BEIJING UNIV OF POSTS & TELECOMM

A ultrasonic positioning method and a ultrasonic positioning system

The invention discloses a ultrasonic positioning method. The method comprises that a ultrasonic wave emitting device generates a ultrasonic signal according to a preset device code and a time code, and transmits the ultrasonic signal; that a client acquires the ultrasonic signal emitted by the ultrasonic wave emitting device; that the client decodes the acquired ultrasonic signal in order to generate the device code and the time code, and transmits the device code and the time code to a server; that the server positions the real-time position of the client according to the device code; that whether the ultrasonic signal is normal is determined according to the time code, and the positional information is forwarded to the client if yes. The invention also discloses a ultrasonic positioning system. The ultrasonic positioning system accurately acquires the ultrasonic signal with a instantaneous frequency measurement algorithm, converts the ultrasonic signal into a frequency domain signal with fast Fourier transform, restores the ultrasonic signal high efficiently, extracts the device code, and achieves the accurate positioning of the client.
Owner:广州光点信息科技股份有限公司

Digital broadband frequency measurement

The present invention relates to a device and method that digitally replicates the analog processing that is normally associated with an instantaneous frequency measurement device. Specifically, the present relates to a digital frequency measurement device comprising: a filter, where the filter receives an input RF signal and transmits an output signal centered around a desired frequency; a limiting amplifier downstream of the filter, where the amplifier receives and amplifies the output signal; a deserializer downstream of the amplifier that continuously samples the output signal from the limiting amplifier; and a digital frequency measurement processor (DFM), where the DFM receives data at a rate of 1 / 16 of the deserializer sample rate. The DFM transforms the data into multiples stages that are combined in order to produce an estimate of the input signal, where the DFM is implemented through a digital processing device.
Owner:BAE SYST INFORMATION & ELECTRONICS SYST INTERGRATION INC

Silicon-based integrated microwave frequency measuring instrument

The invention discloses a silicon-based integrated microwave frequency measuring instrument, which comprises an electro-optical intensity modulator, a frequency classification unit, a frequency selection unit, an instantaneous frequency measurement unit and a Y branch; the electro-optical intensity modulator is used for loading a microwave signal to be measured to an optical carrier to form an optical carrier microwave signal; the Y branch divides the optical carrier microwave signal into two paths with equal intensity, the two paths of the optical carrier microwave signal are respectively sent to the frequency classification unit and the frequency selection unit, the frequency classification unit is used for judging the frequency component and the frequency type of the optical carrier microwave signal, and the frequency selection unit is used for shaping the frequency spectrum and sending the selected frequency band to the instantaneous frequency measurement unit; the instantaneous frequency measurement unit provides two independent linear frequency responses, maps the frequency of the optical carrier microwave signal to the power through the two linear frequency responses, and determines the frequency of the microwave signal to be measured by measuring the power. Therefore, different types of unknown signals can be identified during instantaneous measurement, and the capability of distinguishing complex signals in a complex environment is greatly improved.
Owner:HUAZHONG UNIV OF SCI & TECH

Instantaneous frequency measurement apparatus and measurement method

ActiveCN109361477AMeet the high-precision instantaneous frequency test requirementsMeet the needs of instantaneous frequency measurementTransmitters monitoringFrequency measurement arrangementFrequency spectrumFrequency measurements
The invention discloses an instantaneous frequency measurement apparatus and measurement method, and belongs to the technical field of instantaneous frequency measurement. The apparatus provided by the invention comprises a radio-frequency processing unit, a sampling and frequency mixing unit, an intermediate frequency processing unit, a digital channel processing unit and an operation unit. The real-time monitoring bandwidth implemented by the instantaneous frequency measurement apparatus and measurement method can be up to 26.5 GHz; real-time spectral analysis and instantaneous frequency demodulation are combined, so an instantaneous frequency test for multiple domains and multiple frequency bands is implemented, the requirements of the instantaneous frequency test on large monitoring bandwidth and high precision can be met, and the application range is wider; the implemented dynamic range and sensitivity are higher; with the intermediate frequency gain adaptive adjustment, the instantaneous frequency measurement requirements of different input power signals can be met, and the frequency measurement precision can also be improved; and the implementation scheme is concise, the circuit composition is simple, the technology is mature and high and the implementation cost is low, so the instantaneous frequency measurement apparatus and measurement method have the advantage of verygood cost performance.
Owner:CHINA ELECTRONIS TECH INSTR CO LTD

Bias-voltage-control-based adjustable instantaneous frequency measure system

The invention, which relates to the field of the microwave photonics, provides a bias-voltage-control-based adjustable instantaneous frequency measure system. A first continuous wave laser (11) and a second continuous wave laser (12) are respectively connected with a first polarization controller (21) and a second polarization controller (22); the first polarization controller (21) and the second polarization controller (22) are respectively connected with a polarization beam splitter (3); the polarization beam splitter (3) is connected with a third polarization controller (23); the third polarization controller (23), a radio frequency signal source (5) and a bias voltage source (6) are connected to a light input terminal (41), a radio frequency input terminal (42), and a bias input terminal (43) of a polarization modulator (4); the output of the polarization modulator (4) is connected with a fourth polarization controller (24) connected with a wire grid polarizer (7); and the wire grid polarizer (7) is connected with a single-mode fiber (8) and a wavelength division multiplexing device (9) is used for carrying out shunting. A first photoelectric detector and a second photoelectric detector (101 and 102) respectively detect separated two paths of signals and output the signals to a first input terminal and a second input terminal (131 and 132) of an electric treatment module (13), thereby obtaining an amplitude comparison function.
Owner:BEIJING JIAOTONG UNIV

Stimulated Brillouin scattering microwave frequency measuring device and method based on optical chirp chain

The invention provides a stimulated Brillouin scattering microwave frequency measuring device and method based on an optical chirp chain. The device comprises a first laser, a coupler, a pulsed light modulation light path, a probe light modulation light path, an SBS acting medium and a detector; wherein a light beam output by the first laser is divided into a first light beam and a second light beam through the coupler; the first light beam passes through the pulse light modulation light path to form pump pulse light carrying a microwave signal with a to-be-measured frequency; the second light beam passes through the probe light modulation light path to generate probe light modulated by an optical chirp chain; the pump pulse light and the probe light are injected from the two ends of the SBS acting medium respectively, and an SBS action occurs in the SBS acting medium; and the detector collects the time domain signal, measures the center frequency of the time domain signal, and determines the frequency value of the microwave signal with the frequency to be measured in combination with the Brillouin frequency shift value of the SBS acting medium. By means of the invention, the high-precision single-signal instantaneous frequency measurement is realized.
Owner:HARBIN INST OF TECH

Optical instantaneous frequency measurement device

The invention relates to an optical instantaneous frequency measurement device. The optical instantaneous frequency measurement device sequentially comprises a mode-locked laser, a dispersion component, an electro-optical intensity modulator, a dispersion compensation component, a photoelectric converter and a time interval measurement module. According to the optical instantaneous frequency measurement device in the invention, the limitation of an electronic device is broken through; the instantaneous frequency measurement bandwidth is greatly increased; simultaneously, compared with other optical instantaneous frequency measurement systems, the optical instantaneous frequency measurement device in the invention has the advantages that: multiple frequency signals can be measured at the same time; the measurement result has nothing to do with the input signal amplitude; and furthermore, the frequency sweeping process is unnecessary.
Owner:SHANGHAI JIAO TONG UNIV

Intra-pulse modulation type parameter extraction system and use method

The invention relates to an intra-pulse modulation type parameter extraction system and a use method, and belongs to the technical field of radar signal parameter calibration, and the system comprises a digital channelization module, an instantaneous frequency measurement module, an intra-pulse modulation type parameter extraction module and a radiation source information module; the intra-pulse modulation type parameter extraction system is based on a joint algorithm of digital channelization and instantaneous frequency measurement, the number of channels is D, a digital channelization module comprises D-time decimation filtering and over-threshold detection, and an instantaneous frequency measurement module comprises instantaneous frequency measurement, basic parameter measurement and PDW. Signals output after intermediate frequency data are subjected to D-time decimation filtering are subjected to over-threshold detection screening to obtain a frequency range of the signals, instantaneous frequency measurement is performed in the instantaneous frequency measurement module to obtain an accurate frequency value, basic parameter measurement is performed to obtain arrival time, arrival angle, amplitude and pulse width parameters, and complete pulse description word output is formed through encoding; therefore, the problems of high signal-to-noise ratio, high measurement precision and large operand required in the prior art are solved.
Owner:BEIJING INST OF RADIO METROLOGY & MEASUREMENT

Optical-assisted broadband microwave instantaneous frequency measurement method and device

The invention discloses an optical-assisted broadband microwave instantaneous frequency measurement method and device. Continuous light emitted by a laser firstly enters a carrier suppression type single sideband modulation module to be modulated by a received radio frequency signal to be measured, and a generated optical signal of a single sideband is divided into two branches through a coupler; the upper branch optical sideband enters a Mach-Zehnder interferometer to obtain two port outputs of complementary filtering; optical frequency shift fs from MHz to hundred MHz magnitude is realized after the optical sideband of the lower branch passes through the acousto-optic modulator; the outputs of the two branches are combined and enter the two low-speed photoelectric detectors, and a radio frequency signal with a fixed carrier frequency fs is generated through beat frequency; and an amplitude comparison function is obtained by comparing the amplitudes of the two radio frequency signals, so that the frequency of the microwave signal to be measured is speculated. According to the method, interference of direct current and low-frequency noise is avoided, the whole process is irrelevant to changes of light source power and microwave power, and instantaneous frequency measurement can be achieved in a broadband range.
Owner:CHONGQING UNIV OF POSTS & TELECOMM

Instantaneous frequency measurement method based on FPGA and digital receiver thereof

ActiveCN110208601AQuality improvementSolve the problem of not being able to measure overlapping multi-signalsSpectral/fourier analysisWave based measurement systemsData streamFrequency spectrum
The invention discloses an instantaneous frequency measurement method based on an FPGA and a digital receiver thereof. The method comprises the following steps of: delaying the original data stream byb clock cycles, forming two real sequences with the current data stream, wherein the two real sequences are respectively used as a real part and an imaginary part to obtain complex original data stream signals; inputting the plurality of original data stream signals into an FFT (Fast Fourier Transform) operation module according to the bit width, performing butterfly operation for the output of the FFT module operation module, and inputting the output into a decomposition circuit to obtain frequency spectrums corresponding to two real sequences respectively; calculating a noise threshold according to the two complex frequency spectrums; according to the noise threshold and a set signal-to-noise ratio margin, performing searching by adopting an extreme value to obtain a coarse frequency measurement signal; demodulating and outputting the pulse synchronous signal according to the noise threshold, the signal-to-noise ratio margin and the coarse frequency measurement signal; obtaining a real part value and an imaginary part value corresponding to the coarse frequency measurement signal according to the coarse frequency measurement signal and the complex frequency spectrums; measuringthe frequency by adopting a phase difference method; and finally, fusing data to output a frequency measurement result. The digital receiver includes the FPGA implementation that integrates the above-described method.
Owner:CHENGDU SEEKCON MICROWAVE COMM

Broadband adaptive frequency tracking system and method

PendingCN108169742ASolve the technical problem of IF signal deviationRadio wave reradiation/reflectionIntermediate frequencyFrequency measurements
The invention provides a broadband adaptive frequency tracking system and a method. The system comprises an instantaneous frequency measurement module, a storage module, a control code generation module and a frequency integration module, wherein the instantaneous frequency measurement module is used for carrying out frequency measurement on a received emission pulse signal and acquiring a frequency code; the storage module is used for storing an association relation table of the frequency code and a control code; the control code generation module is connected to the instantaneous frequency measurement module and the storage module and is used for searching and generating the control code from the storage module according to the frequency code measured by the instantaneous frequency measurement module; and the frequency integration module is connected to the control code generation module and is used for generating a local oscillation signal according to the control code generated bythe control code generation module. In each repetition period of the emission pulse signal, actual intermediate frequency signals after frequency mixing of a radar receiver are in an optimum processing frequency band so that the adaptive rapid frequency tracking function of the received local oscillation signal to the emission pulse signal is realized; and receiver performance is guaranteed not tobe influenced by emission frequency drift and tactical performance of a radar integration machine is ensured.
Owner:上海微抗电子技术有限公司

Instantaneous frequency measuring device based on optical power monitoring

The invention discloses an instantaneous frequency measuring device based on optical power monitoring, and relates to the field of optoelectronic devices and microwave photonics. The device comprises a continuous wave laser (1), a polarization controller (2), a signal generator (3), an electric power divider (4), an electric delay line (5), an optical power divider (6), an electric power divider (7), an electric power divider (8), an I / Q modulator (9), an I / Q modulator (10), an optical power meter (11) and an optical power meter (12). By monitoring the power values of the two optical power meters, the frequency of the radio frequency signal can be calculated. By changing the delay amount of the electric delay line (5), the measurement range and measurement error of the instantaneous frequency measurement can be adjusted.
Owner:BEIJING JIAOTONG UNIV

Microwave bandwidth folding and receiving method

InactiveCN102088296AWith bandwidthFrequency selectiveTransmissionMicrowaveInstantaneous frequency measurement
The invention discloses a microwave bandwidth folding and receiving method, comprising: folding the bandwidth of an input band in half to form high and low sub-bands; shifting down the high sub-band to the low sub-band; outputting the low sub-band in which a signal is positioned under the control of a folding code; detecting the sequence of video pulses simultaneously from the high and low sub-bands; and outputting the signal mark (s1) and the folding code (m0). Every time the folder folds, the bandwidth is reduced by double. The normalized error radio frequency, characteristic frequency and absolute frequency are output by folding the bandwidth step by step. The invention has advantages of wide band, good frequency selectivity as well as an instantaneous frequency measurement function without being interfered by overlapped signals. The intercept probability is close to 100%. Due to output normalization, fine frequency measurement becomes possible and a wideband-based digital receiver can be directly obtained. In the invention, conventional components are organically combined and are easy to manufacture.
Owner:CHENGDU LATEST ELECTRONICS TECH

Radar signal instantaneous frequency measurement method and device

The invention discloses a radar signal instantaneous frequency measurement method and device, and the method comprises the steps: dividing laser from a laser into two paths, and enabling the two paths of laser to serve as optical carriers; taking a radar signal to be measured as a modulation signal to carry out amplitude modulation on one path of optical carrier, and generating a pump optical signal; performing frequency modulation on the other path of optical carrier by using the sweep frequency signal as a modulation signal to generate a probe light input signal; inputting the pump light signal and the probe light input signal into an optical fiber section in opposite directions, and performing energy conversion between the pump light and the probe light by using an optical fiber stimulated Brillouin scattering effect; and performing photoelectric detection on the transmitted probe light output signal, and determining a corresponding frequency sweep signal frequency value when the intensity of the output electric signal is maximum. The problems of small frequency measurement range and low benefit in the prior art are solved.
Owner:BEIJING INST OF RADIO METROLOGY & MEASUREMENT

Broadband instantaneous frequency measuring and tracking device

The invention discloses a broadband instantaneous frequency measuring and tracking device, which takes an FPGA chip as a control core, realizes broadband signal input and instantaneous frequency measurement through an instantaneous frequency measurement unit of a multistage frequency division structure, and then process a measurement result of the instantaneous frequency measurement unit by an FPGA to generate a high-speed digital signal, wherein the high-speed digital signal is configured to a frequency agility unit, and the frequency agility unit outputs an analog signal with the same carrier frequency as the input signal by adopting different tracking modes according to the frequency of the input signal, so that the functions of rapid frequency measurement and tracking are realized.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA +1

A silicon-based integrated microwave frequency measuring instrument

The invention discloses a silicon-based integrated microwave frequency measuring instrument, which comprises an electro-optical intensity modulator, a frequency classification unit, a frequency selection unit, an instantaneous frequency measurement unit and a Y branch; the electro-optical intensity modulator is used for loading a microwave signal to be measured to an optical carrier to form an optical carrier microwave signal; the Y branch divides the optical carrier microwave signal into two paths with equal intensity, the two paths of the optical carrier microwave signal are respectively sent to the frequency classification unit and the frequency selection unit, the frequency classification unit is used for judging the frequency component and the frequency type of the optical carrier microwave signal, and the frequency selection unit is used for shaping the frequency spectrum and sending the selected frequency band to the instantaneous frequency measurement unit; the instantaneous frequency measurement unit provides two independent linear frequency responses, maps the frequency of the optical carrier microwave signal to the power through the two linear frequency responses, and determines the frequency of the microwave signal to be measured by measuring the power. Therefore, different types of unknown signals can be identified during instantaneous measurement, and the capability of distinguishing complex signals in a complex environment is greatly improved.
Owner:HUAZHONG UNIV OF SCI & TECH
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