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90 results about "Frequency synthesis" patented technology

Frequency modulation synthesis (or FM synthesis) is a form of sound synthesis where the frequency of a waveform, called the carrier, is changed by modulating its frequency with a modulator. The frequency of an oscillator is altered "in accordance with the amplitude of a modulating signal." ( Dodge & Jerse 1997, p. 115)

Microwave and millimeter wave near-field subsurface microscopic imaging device and method based on signal interference

The invention belongs to the technical field of near-field imaging, and particularly relates to a microwave and millimeter wave near-field subsurface microscopic imaging device and method based on signal interference, and the device comprises a vector network analyzer, a signal separation device, a phase adjustment device, a semi-steel coaxial line, a displacement platform, and an industrial control computer. The vector network analyzer comprises a signal separation unit, a frequency synthesis source, a first receiver and a second receiver, wherein the frequency synthesis source, the first receiver and the second receiver are respectively connected with the signal separation unit and used for generating microwave and millimeter wave test signals. The signal separation device is respectively connected with the vector network analyzer, the phase adjusting device and the semi-steel coaxial line, and the displacement table is connected with the vector network analyzer through the industrial personal computer; the tail end of the semi-steel coaxial line, which is far away from the signal separation device, is provided with a conical needle tip-shaped near-field probe; and the needle tip of the near-field probe is vertical to the surface of a to-be-detected sample arranged on the displacement table.
Owner:THE 41ST INST OF CHINA ELECTRONICS TECH GRP

Broadband intermediate-frequency heterogeneous integrated communication transceiving micro module and three-dimensional packaging method

The invention designs a broadband intermediate-frequency heterogeneous integrated communication transceiving micro module and a three-dimensional packaging method, and belongs to the technical field of advanced packaging. The micro module comprises a TSV silicon adapter plate, a Fan-out module, an HTCC ceramic substrate and a digital chip. The TSV silicon adapter plate adopts a high-resistance silicon substrate, and a coaxial shielding TSV structure is arranged on the TSV silicon adapter plate and comprises an inner layer signal through hole and an outer layer grounding layer. A frequency synthesizer chip and a radio frequency chip are embedded in the Fan-out module, and high-density horizontal interconnection is realized through a plurality of redistribution layers. The HTCC ceramic substrate is of a multi-layer laminated structure, and an impedance matching network is arranged in the HTCC ceramic substrate. The three-dimensional packaging method comprises the steps of TSV silicon adapter plate preparation, Fan-out module processing, digital chip stacking and system-level integration. High-density packaging of the radio frequency chip and the digital chip is achieved through the three-dimensional heterogeneous integrated architecture, and low-loss transmission of broadband signals is guaranteed through the coaxial shielding TSV structure and the impedance matching network.
Owner:SHANDONG INST OF AEROSPACE ELECTRONICS TECH

Beat frequency comparison device mediated by optical frequency comb

The invention discloses a beat frequency comparison device mediated by an optical frequency comb. The beat frequency comparison device comprises the optical frequency comb, a first frequency stabilized laser, a first beat frequency device, a first frequency mixer, a first high-pass filter, a second frequency stabilized laser, a second beat frequency device, a second frequency mixer, a second high-pass filter, a DDS signal generator, a third frequency mixer and a low-pass filter. Frequency-stabilized lasers output by the first frequency-stabilized laser and the second frequency-stabilized laser and an optical frequency comb output by the optical frequency comb are subjected to beat frequency in the first beat frequency device and the second beat frequency device respectively, and first beat frequency and second beat frequency are obtained; the first beat frequency and the second beat frequency are mixed with the carrier envelope offset frequency of the optical frequency comb, and a first sum frequency and a second sum frequency are filtered out; the first sum frequency obtains a synthetic frequency through direct digital frequency synthesis; the second sum frequency and the synthetic frequency are mixed in the third mixer, and then the difference frequency is filtered out through the low-pass filter. According to the invention, beat frequency comparison of frequency-stabilized lasers with different wavelengths can be realized, and the influence of the stability of the optical frequency comb is avoided.
Owner:BEIJING CHANGCHENG INST OF METROLOGY & MEASUREMENT AVIATION IND CORP OF CHINA

Direct digital synthesis method and system based on mixed fraction proportion

The invention discloses a direct digital synthesis method and system based on a mixed fraction proportion. The method comprises the following steps: determining an integer frequency control word, a numerator frequency control word and a denominator frequency control word based on a target frequency, a sampling frequency and a bit width of a phase accumulator; performing a fractional phase accumulation operation based on the sampling frequency, the molecular frequency control word, and the phase accumulator to generate a carry signal; performing integer phase carry and accumulation operation in parallel with the fractional phase accumulation operation according to the sampling frequency, the integer frequency control word and the phase accumulator to obtain an integer phase value; and acquiring a waveform digital amplitude corresponding to the integer phase value, and performing signal conversion according to the waveform digital amplitude to obtain an amplitude signal corresponding to the target frequency so as to improve the precision of the frequency synthesis signal.
Owner:CHENGDU WEIDE QINGYUN ELECTRONICS CO LTD

Multi-channel microwave signal generation method and system with fixed initial phase

The invention provides a multi-channel microwave signal generation method and system with a fixed initial phase, and the method comprises the steps: responding to a triggering signal received by a high-speed clock synchronization module after a pre-configured synchronous clock signal is inputted to the high-speed clock synchronization module; the high-speed clock synchronization module generates a sampling clock signal and a logic clock signal based on the synchronous clock signal, responds to the logic clock signal and inputs the logic clock signal to the high-speed controller, the high-speed controller generates a signal description word while triggering signal input, responds to the sampling clock signal and inputs the sampling clock signal to the direct digital frequency synthesis module; and the direct digital frequency synthesis module generates an analog fundamental frequency signal required by the multi-channel microwave signal source based on the signal description word, responds to the analog fundamental frequency signal and inputs the analog fundamental frequency signal to the phase-locked loop device, and the phase-locked loop device outputs a final target microwave signal.
Owner:ZHONGXING LIANHUA TECH BEIJING CO LTD

Method and device for constellation time keeping in free operation state of satellite-borne atomic clock

The invention provides a method for constellation time keeping in a free operation state of a satellite-borne atomic clock, and the method comprises the steps: generating an adjustable second time frequency signal through frequency synthesis based on a first time frequency signal outputted by the satellite-borne atomic clock; comparing and measuring the phase difference between the two and sending the phase difference to an inter-satellite link; through inter-satellite measurement and interaction, obtaining a clock error between the second time frequency signals of all satellites, and converting to obtain a clock error between the first time frequency signals of all satellites; and on the basis, a clock difference parameter between the constellation time and the first time-frequency signal is calculated and converted into a clock difference parameter between the constellation time and the second time-frequency signal, a frequency adjustment parameter is generated through a control algorithm, and the second time-frequency signal is controlled to gradually approach the constellation time. The invention further provides a device for constellation time keeping in the free operation state of the satellite-borne atomic clock. Therefore, the free operation requirement and the irregular frequency modulation requirement of the satellite-borne atomic clock under the navigation constellation autonomous time keeping scene can be considered, and the constellation autonomous time keeping precision and the user service performance are improved.
Owner:CHINA ACADEMY OF SPACE TECHNOLOGY

Transformer-coupled input buffer for frequency synthesis

A frequency synthesis circuit includes a first inductor coupled to receive a first input signal at an input frequency, and a second inductor coupled to receive second input signal at the input frequency and out-of-phase relative to the first input signal. The circuit has first and second transistors with control terminals coupled to the first and second inductors, respectively. A first resonant tank of an inductor in parallel with a capacitor is coupled between a power supply terminal and the first transistor. A second resonant tank of an inductor in parallel with a capacitor is coupled between the power supply terminal and the second transistor. The first and second resonant tanks are tuned to a selected harmonic of the input frequency. An injection-locked oscillator has inputs coupled to the first and second transistors.
Owner:TEXAS INSTRUMENTS INC

Satellite navigation signal system design method based on hybrid modulation of direct sequence spread spectrum and frequency hopping

The present invention relates to a satellite navigation signal system design method based on hybrid modulation of direct sequence spread spectrum and frequency hopping. The method comprises: spreading code sequences of multiple signal components being modulated and being then hybrid-multiplexed with signal components corresponding to a same frequency point, and forming a baseband code sequence on the basis of power allocation ratios of the signal components; on the basis of environment conditions, performing signal separation on the signal components corresponding to the baseband code sequence, in order to obtain separated radio frequency signals, and performing recombination and modulation on the signals; if the separated radio frequency signals are authorized signals, controlling a frequency hopping pattern by means of a frequency hopping code sequence, and performing hybrid frequency synthesis modulation on the basis of a center frequency point of the frequency hopping pattern and the frequency of the authorized signals; if the separated radio frequency signals are unauthorized signals, performing direct combining and radio frequency modulation on the unauthorized signals on the basis of a signal frequency point, in order to obtain recombined signal components; and performing signal power amplification on the basis of a center frequency point difference of the recombined signal components, in order to obtain direct sequence spread spectrum navigation signals. The method can greatly improve the anti-jamming capability of navigation signals.
Owner:NAT UNIV OF DEFENSE TECH

Noise frequency modulation signal generation device

PendingCN121690074ANoise generationDigital function generatorsNoise bandwidthTelecommunications
The invention discloses a noise frequency modulation signal generation device, which is realized based on a field programmable gate array (FPGA), and adopts the following method steps: S1, in the FPGA, constructing an arbitrarily distributed random number generator to obtain random numbers conforming to distribution; s2, linearly mapping the obtained random number into a frequency modulation noise bandwidth by using a linear mapping method to obtain a random frequency conforming to Gaussian distribution; and S3, converting the obtained random frequency into frequency modulation noise by using a direct digital frequency synthesis technology. Complex linear algebraic operation is simplified into integer addition, subtraction and shifting, FPGA parallelism and special hardware resources are fully utilized, high speed, low resources and high statistical quality are considered, and a reliable hardware noise source is provided for scenes such as communication simulation and radar interference.
Owner:NAT INNOVATION INST OF DEFENSE TECH PLA ACAD OF MILITARY SCI

Direct digital frequency synthesizer based on rbf neural network with stage-by-stage optimization

The application discloses a direct digital frequency synthesizer based on RBF neural network of phased optimization, which comprises a phase accumulator responsible for generating a phase signal, an RBF neural network module responsible for converting the phase signal into a digital amplitude signal, a digital-analog converter responsible for converting the digital amplitude signal into a low-frequency sawtooth signal and a low-pass filter responsible for converting the sawtooth signal into a smooth analog signal. The RBF neural network module comprises a hidden layer and an output layer, each node in the hidden layer has a corresponding radial basis function, so as to map a corresponding characteristic value for each input phase information, multiply the corresponding characteristic value of each node with the corresponding weight in the output layer, and then sum up to obtain an amplitude value corresponding to the phase information. Compared with the prior art, the application introduces the RBF neural network, so that the direct digital frequency synthesizer has stronger scalability and adaptability when processing complex and nonlinear frequency synthesis tasks.
Owner:NANJING UNIV OF POSTS & TELECOMM

Radar beacon device with power measurement feedback adjustment and power measurement feedback adjustment method

The invention discloses a radar beacon device with power measurement feedback adjustment and a power measurement feedback adjustment method. The radar beacon device comprises a data processing unit used for receiving parameters and control instructions, processing uploaded measurement power information and controlling an attenuation value; the signal processing unit is used for outputting a synchronous trigger signal to the power measuring unit; the microwave frequency conversion unit is used for realizing receiving, modulation and frequency synthesis of radio frequency signals; the power measurement unit is used for collecting observation signals, performing synchronous detection by combining with the synchronous trigger signals, and outputting measurement data to the data processing unit; and the display control unit is used for setting equipment working parameters and displaying the current state and power information of the equipment. According to the invention, the power measuring device is additionally arranged to monitor a transmitting signal, and a monitoring result is fed back to the control unit to control the transmitting link attenuator to set a corresponding attenuation value, so that the actual output power is consistent with the set power value, the problem of outputting absolute power is solved, and the requirement of high power precision is met.
Owner:YANGZHOU YUAN ELECTRONICS TECH CO LTD

A low phase noise phase-locked loop spurious rejection system and method

The application relates to the field of frequency synthesis technology and discloses a low-phase-noise phase-locked loop spurious suppression system and method, which comprises a control module, an oscillator module connected with the output end of the control module, wherein the oscillator module comprises a plurality of oscillator units, a mixing and filtering module connected with the output end of the oscillator module, which is used for mixing and filtering a plurality of reference frequency signals output by the oscillator module and outputting a target reference signal, a signal selection switch used for receiving a control instruction sent by a central processing unit, a fractional-N phase-locked loop used for receiving a system reference clock signal and outputting a radio frequency output signal, and the central processing unit used for receiving a target output frequency signal and determining the system reference clock signal based on the target output frequency signal and the target reference signal. While the spurious is suppressed, the super-low phase noise characteristic of the reference source is maintained, the output frequency is continuously and accurately kept before and after switching, and the low phase noise and low spurious are simultaneously realized.
Owner:NANJING PEGO MEASUREMENT&CONTROL TECH CO LTD

L-band transmit-receive front-end module

The invention provides an L-band transceiving front-end module. The L-band transceiving front-end module comprises a control unit, and a receiving channel, a transmitting channel, a self-checking circuit, a frequency synthesis unit and a power supply unit which are connected with the control unit, the receiving channel adopts a secondary frequency conversion superheterodyne architecture and is used for converting a received radio frequency signal into an intermediate frequency signal and outputting the intermediate frequency signal to the digital processing part, and the transmitting channel adopts a primary frequency conversion architecture and is used for converting an input intermediate frequency signal into a radio frequency signal and outputting the radio frequency signal; and the frequency synthesis unit is used for providing local oscillation signals for the frequency mixers of the receiving channel and the transmitting channel. According to the invention, the receiving and transmitting isolation is improved, the interference of transmitting on receiving is reduced, the connection between the receiving channel and the antenna in the transmitting mode can be cut off through the design of the receiving on-off switch, the transmitting signal is effectively prevented from entering the receiving channel in series, the purity of the receiving signal is ensured, and the stable realization of the receiving function is ensured.
Owner:XIAN LINGBEI ELECTRONIC TECH CO LTD

Hybrid fractional ratio based direct digital synthesis method and system

The application discloses a direct digital synthesis method and system based on a mixed fractional ratio, and the method comprises the following steps: determining an integer frequency control word, a numerator frequency control word and a denominator frequency control word based on a target frequency, a sampling frequency and a bit width of a phase accumulator; performing a fractional phase accumulation operation based on the sampling frequency, the numerator frequency control word and the phase accumulator to generate a carry signal; performing an integer phase carry and accumulation operation in parallel with the fractional phase accumulation operation according to the sampling frequency, the integer frequency control word and the phase accumulator to obtain an integer phase value; and obtaining a waveform digital amplitude value corresponding to the integer phase value to perform signal conversion according to the waveform digital amplitude value to obtain an amplitude signal corresponding to the target frequency, so that the accuracy of a frequency synthesis signal is improved.
Owner:CHENGDU WEIDE QINGYUN ELECTRONICS CO LTD

Time amplifier with self-cancellation of quantization noise and fractional-N phase-locked loop

PendingCN122316340Areduce designPhase noise suppressionLow noiseConverters
This invention discloses a time amplifier with self-cancelling quantization noise and a fractional-frequency division phase-locked loop (PLL), belonging to the field of frequency synthesis technology. The self-cancelling quantization noise time amplifier of this invention is based on a resistor-discharge type time amplifier. A control signal containing quantization error information is output through a slow-slope control signal generator to control the slow-discharge path of the time amplifier. This achieves K-fold time error amplification while simultaneously canceling fractional-frequency division quantization noise. The PLL architecture built based on this amplifier eliminates the need for a large-delay loop digital-to-time converter. The phase noise of the slow-slope control signal generator is suppressed by the time amplification gain, breaking the performance trade-off of traditional architectures. This invention achieves a low-noise, low-power, and high-linearity fractional-frequency division PLL design without degrading the performance of the time amplification phase detector.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA

Digital frequency synthesizer, signal compensation method, SOC chip and electronic device

The application relates to a digital frequency synthesizer, a signal compensation method, an SOC chip and electronic equipment, and belongs to the integrated circuit field.The digital frequency synthesizer comprises a digital frequency synthesis unit, a phase compensation unit and a phase adjustment unit; the digital frequency synthesis unit is used for generating a first clock signal with a first specified duty cycle according to an externally input first digital phase enable binary code and a multi-path initial phase clock signal; the phase compensation unit is used for generating a target compensation clock signal with a corresponding phase width according to required phase accuracy; and the phase adjustment unit is used for generating an output clock signal with a second specified duty cycle according to the target compensation clock signal and the first clock signal. The first clock signal is compensated by generating the target compensation clock signal with the required phase width, so that a clock signal with an arbitrary duty cycle can be output, and the problem that the existing digital frequency synthesizer can only output a clock signal with a specific frequency is effectively improved.
Owner:HYGON INFORMATION TECH CO LTD

5GNTN low earth orbit satellite frequency conversion device for realizing broadband coverage

PendingCN122026816AGain controlRadio transmissionFrequency coverageFrequency conversion
The invention relates to a 5GNTN low earth orbit satellite frequency conversion device for realizing broadband coverage, which comprises a reference clock unit, a frequency conversion unit, a local oscillation leakage suppression unit, a gain selection control unit and a frequency synthesis control unit, and is characterized in that the output end of the reference clock unit is connected with the input end of the frequency conversion unit; the output end of the frequency conversion unit is connected with the input end of the local oscillation leakage suppression unit, the output end of the local oscillation leakage suppression unit is connected with the input end of the gain selection control unit, and the output end of the gain selection control unit is connected with the input end of the frequency synthesis control unit. By adopting the 5GNTN low earth orbit satellite frequency conversion device for realizing broadband coverage, through the design of broadband and large dynamic gain, the requirement of frequency coverage of a 5G NTN low earth orbit satellite from an s wave band to a ka wave band at present is met, and meanwhile, an effective and broadband coverage frequency conversion means can be provided for navigation satellites, military satellites and the like.
Owner:TRANSCOM INSTR

Frequency synthesis circuit and method

The embodiment of the invention discloses a frequency synthesis circuit and method, and the circuit comprises a power divider, the input end of the power divider is connected with a reference clock signal, and the power divider is used for distributing the reference clock signal into a plurality of sub-reference signals, and outputting the plurality of sub-reference signals through the corresponding output end of the power divider; wherein the sub reference signals are consistent in phase and equal in power; a plurality of phase-locked frequency multiplication channels, the input end of each phase-locked frequency multiplication channel is correspondingly connected with the output end of the power divider, and the phase-locked frequency multiplication channels are used for performing phase-locked frequency multiplication processing according to the corresponding sub reference signals to generate first frequency signals; and the input end of the synthesis control module is connected with the output ends of the plurality of phase-locked frequency multiplication channels, and the synthesis control module is used for synthesizing the plurality of first frequency signals to generate a final output signal. According to the technical scheme provided by the embodiment of the invention, the signals with the same frequency and phase correlation are generated through the multiple phase-locked frequency multiplication channels, so that the frequency spectrum purity of the signals is improved.
Owner:FUDAN UNIVERSITY +1

Low-phase noise signal generating device

The invention discloses a low-phase noise signal generation device, which belongs to the technical field of low-phase noise signal generation, and comprises a power supply module, a VPX main control board, a baseband unit, a reference unit, a local oscillator and clock unit, a frequency reference unit and an output unit, the local oscillator and clock unit generates a clock signal and a local oscillator signal with low phase noise, and the baseband unit generates a baseband signal with low phase noise. The frequency reference unit obtains a broadband fine-step frequency reference signal, and the output unit finally generates an output signal of 10 MHz to 40 GHz. According to the low-phase-noise signal generation device, the fine frequency resolution advantage of the DDS technology and the broadband and low-phase-noise advantages of the analog direct frequency synthesis technology are perfectly combined through the original three-stage architecture of baseband DDS fine step generation, local oscillator PLL large step phase locking and direct frequency synthesis filling. Finally, the frequency of the output signal covers the ultra-wide range of 10 MHz to 40 GHz, and meanwhile, the ultra-fine frequency stepping is kept.
Owner:BEIJING INST OF RADIO METROLOGY & MEASUREMENT

Integrated millimeter wave radar radio frequency front-end system

The invention discloses an integrated millimeter-wave radar radio frequency front-end system, which relates to the technical field of millimeter-wave radars and comprises a frequency synthesis module, a transmitting channel and a receiving channel. The frequency synthesis module generates and outputs a high-band linear frequency modulation signal. The input end of the transmitting channel is connected with the frequency synthesis module, and the transmitting channel comprises a frequency multiplication link, a power amplifier based on the gallium nitride technology and a first filter and is used for performing up-conversion processing on signals to W wave bands and performing antenna radiation after power amplification and harmonic suppression. And the receiving channel local oscillation end is connected with the frequency synthesis module to obtain a local oscillation signal, the signal input end is connected with an antenna, and the receiving channel comprises a low-noise amplifier, a second filter, an image rejection filter and a frequency mixer and is used for amplifying, filtering and down-converting the W-band echo signal. The invention has the advantages of miniaturization, low loss, low phase noise and high efficiency.
Owner:FUTENG TECH BRANCH OF QUZHOU GUANGMING POWER INVESTMENT GRP CO LTD

Laser radar dynamic scanning system and method for capturing and tracking space non-cooperative target

PendingCN121763300AImprove the ability to capture and track non-cooperative targetsincrease coverageElectromagnetic wave reradiationTarget capturePhase difference
The invention discloses a laser radar dynamic scanning system and method for capturing and tracking a spatial non-cooperative target, and the method comprises the steps: employing a DDS direct digital frequency synthesis method based on an LUT for a dual-axis galvanometer waveform generation module, generating a driving waveform of a dual-axis galvanometer, adjusting the address of a phase accumulator in real time according to a prediction position outputted by a position calculation and prediction module, and achieving the real-time detection of the dual-axis galvanometer. And the phase adjustment of the output waveform of the double-shaft galvanometer is realized. The dual-axis galvanometer with different phase differences outputs a Lissajous image formed by waveforms, the coverage rate of a scanning track can be effectively improved, and the capturing probability is improved on the premise that the scanning bandwidth is not changed.
Owner:BEIJING INST OF CONTROL ENG

Acoustic-electric composite detection device

The invention relates to the technical field of electronic detection, in particular to an acoustoelectric composite detection device which comprises a radar antenna front end, a passive acoustic sensor array, a multi-channel data acquisition module, a frequency synthesis module, a signal processing module, a data processing module and a display control module. The radar antenna front end obtains target space information; the passive sound sensor array receives sound wave vibration signals; the multi-channel data acquisition module is used for synchronously acquiring radar and sound signals; the frequency synthesis module provides time synchronization; the signal processing module extracts target features; the data processing module resolves target information through a data fusion algorithm and performs intelligent identification; and the display control module realizes information visualization and control. According to the invention, through cooperative detection and data fusion of radar and acoustics, the detection probability, the classification precision and the anti-interference capability of low, slow and small targets are effectively improved.
Owner:SHANGHAI SPACEFLIGHT ELECTRONICS & COMM EQUIP RES INST

Frequency control array transmitting system based on DDS and PLL

The application discloses a frequency control array transmitting system based on DDS and PLL, which comprises a crystal oscillator source power division module, a DDS excitation ring-in mixed frequency phase-locked loop circuit module, a DDS local oscillator+phase-locked loop PLL2 circuit module, a phase-locked loop PLL1 circuit module, a ring-out mixed frequency power division circuit module and a FPGA control module. The application realizes that the 8-way reference carrier is 17GHz and the frequency offset of the adjacent two transmitting channels is 4MHz through the ring-in-ring-out mixed frequency phase-locked loop+DDS frequency synthesis and the crystal oscillator source power division module, and the frequency source circuit has good characteristics such as high frequency resolution and low phase noise.
Owner:NANJING UNIV OF SCI & TECH

Terahertz frequency synthesis system and method based on nonlinear metasurface

The invention provides a terahertz frequency synthesis system and method based on a nonlinear metasurface, and the system comprises a frequency obtaining module which obtains at least two frequencies; and the frequency synthesis module inputs at least two frequencies into the preset metasurface structure so as to generate a local magnetic field in a third direction and a local electric field in a first direction at the input frequencies, and drives free electrons in a substrate of the preset metasurface structure to perform non-harmonic oscillation along the first direction and the second direction based on the local magnetic field and the local electric field, terahertz synthesis frequencies corresponding to the first direction polarization and the second direction polarization are radiated. Wherein the preset metasurface structure comprises a substrate and a concentric split ring resonator array arranged on the substrate. According to the invention, an efficient and artificially controllable nonlinear effect is realized, the fundamental defect of weak nonlinearity of a natural material in a terahertz wave band is overcome, and a highly integrated scheme is provided for manufacturing an ultra-wideband and flexible-frequency terahertz source and a nonlinear device.
Owner:TSINGHUA UNIVERSITY

A Method and System for Single-Carrier Symbol Correction in Narrowband IoT Uplink Based on Costas Ring

This invention discloses a method and system for uplink single-carrier symbol correction in narrowband IoT based on a Costas ring, supporting the narrowband IoT protocol specifications defined in 3GPP Release 13. This invention combines the Costas ring with the characteristics of narrowband IoT uplink, utilizing software-defined radio equipment to acquire uplink single-carrier signals. By reconstructing the Costas ring structure, a nonlinear phase detector and a low-pass filter are jointly designed to form a loop filter with joint gain. A digital frequency synthesis module replaces the traditional voltage-controlled oscillator, dynamically compensating for symbol frequency offset and phase distortion based on the error signal output from the Costas ring, thereby completing the demodulation of the real narrowband RF signal. This invention solves the symbol distortion problem caused by frequency offset, multipath effects, and hardware nonlinearity in narrowband IoT scenarios, and can significantly reduce the communication bit error rate compared to traditional channel estimation schemes.
Owner:ZHEJIANG UNIV

Reference source and satellite communication system

The invention provides a reference source and a satellite communication system.The reference source comprises an atomic clock, a first phase-locked loop, a low-frequency crystal oscillator, a frequency doubling filter circuit, a second phase-locked loop, a high-frequency crystal oscillator and an output device.A miniaturized design scheme is adopted, an ultra-thin rubidium clock, a constant-temperature crystal oscillator and an ultra-low phase noise crystal oscillator are arranged in the reference source; the system has the characteristics of small size and low cost, meets the application requirements of a miniaturized or highly integrated scene, and has a wide prospect; the multi-stage frequency synthesis technology is adopted, so that the output reference signal has the characteristics of high speed, stability and low phase noise, the requirements of the fields of time-frequency measurement, radar detection and the like on the reference source are met, and the application range is wide.
Owner:BEIJING INST OF RADIO METROLOGY & MEASUREMENT

A SAR imaging method, system, apparatus and storage medium

The application discloses a SAR imaging method, system, device and storage medium, and the method comprises the following steps: acquiring original echo data; the original echo data is a random step linear frequency modulation waveform; performing decoupling processing on the original echo data to obtain a target signal; the decoupling processing comprises inclination processing and azimuth resampling; performing frequency synthesis processing on the target signal based on a full grid correction matrix to obtain a focused signal; the frequency synthesis processing comprises coarse Doppler extraction and positioning, full grid Doppler correction, sampling rearrangement and series connection and polar coordinate radial compression; performing angle fine focusing processing on the focused signal to obtain a SAR focused image; the angle fine focusing comprises angle signal recovery, phase compensation, angle wave number interpolation and polar coordinate angle compression. The application can effectively improve the problem that the distance focusing performance of the existing processing method decreases with the increase of the azimuth angle, greatly improves the distance focusing performance, and can be widely applied to the technical field of SAR imaging.
Owner:SUN YAT SEN UNIV

Miniaturized W-band ultra-large phased array system

The present application relates to the technical field of phased array radar, and particularly relates to a miniaturized W-band ultra-large-scale phased array system.The present application comprises: a W-band array antenna unit, a 12-way receiving down-conversion unit, a 1-way transmitting up-conversion unit, a digital baseband processing unit, a wave control unit, a digital baseband processing unit, a power supply processing unit; the W-band array antenna unit, 48 groups of transceiving multifunctional front ends, the 12-way receiving down-conversion unit, the 1-way transmitting up-conversion unit, the digital baseband processing unit, the wave control unit, a frequency synthesis unit, and the power supply processing unit are integrated in one substrate.The present application reduces the connection points and interfaces between separated modules in conventional design, reduces the system failure probability caused by poor connection, contact failure and the like, and improves the reliability and stability of the system.
Owner:NANJING BOHAI MICROSYSTEM CO LTD

High-voltage frequency signal modulation device and method

The invention discloses a high-voltage frequency signal modulation device and method, and relates to the field of airborne radar laser modulation, the device is integrated on a circuit board, and the device comprises a control module, a direct digital frequency synthesis driving module, a pulse modulation signal module, a frequency shift modulation signal module, a thermal adjustment bias driving module, a photoelectric detection module and a laser module; the control module is connected with the above modules to realize control and feedback, and the direct digital frequency synthesis driving module is connected with the pulse modulation signal module and the frequency shift modulation signal module to generate a differential voltage signal. And the pulse modulation signal module, the frequency shift modulation signal module, the thermal adjustment bias driving module and the photoelectric detection module are respectively connected with the laser module to realize driving and detection. Through modular integrated design, stable output of high-voltage frequency shift modulation signals, closed-loop control of laser light emitting characteristics and cooperation of multiple modulation signals are realized, and the integration degree, accuracy and stability of airborne radar laser modulation are improved.
Owner:ZHUHAI GUANGHENG TECH CO LTD

High-bit-rate multi-index continuous phase modulation signal receiver

The invention discloses a high-bit-rate multi-index continuous phase modulation signal receiver which comprises a frequency conversion and conditioning module, an AD daughter card module, a frequency synthesis module, an FPGA chip 1 and an FPGA chip 2. Wherein the frequency conversion and conditioning module is configured to complete down-conversion and AGC (Automatic Gain Control) of an S-band radio frequency signal and output an S-band intermediate frequency signal; the AD daughter card module is configured to convert a received S-band intermediate frequency signal into an intermediate frequency digital signal; the frequency synthesis module is configured to complete system work clock generation; the FPGA chip 1 is configured to complete Doppler frequency capture of a received intermediate frequency digital signal, send the captured signal to the FPGA chip 2, receive a demodulation information sequence fed back by the FPGA chip 2 to complete LDPC decoding, descrambling and frame synchronization of corresponding data, and output telemetry data; the FPGA chip 2 is configured to perform carrier phase tracking, modulation index synchronization, timing synchronization and sequence detection on received data.
Owner:10TH RES INST OF CETC