346 results about "Frequency mixing" patented technology

The invention discloses an autonomous positioning method of an unmanned system based on integration of microwave distance measurement and inertial navigation, and belongs to the field of application of a cross technology of navigation positioning and signal processing. In an unmanned system, a filter is tightly combined with an inertial navigation system and a microwave distance measurement positioning system and is regarded as a navigation positioning system, a motion track of a target carrier is calculated, and a sensor observation model fusing two independent inertial navigation systems of inertial navigation and micro navigation in the navigation positioning system is constructed; the method comprises the following steps of: reflecting an interference result of a microwave signal and a reference signal by a solid-state spin detection object, and performing FFT (Fast Fourier Transform) on each reflected microwave signal after frequency mixing to finish microwave distance measurement; on the basis of forming distance calculation, position results output by a distance measurement positioning algorithm are fused, random errors of the system are compensated by adopting an error compensation algorithm, errors of the inertial navigation system are corrected, covariance is updated and corrected according to an observation matrix and Kalman gain, and intelligent autonomous control positioning of the system is realized.

The invention discloses a microwave reflectometer system. An arbitrary waveform generator generates a microwave signal through an X-Ku signal source unit; the coaxial directional coupler divides the generated microwave signal into two paths, one path enters the transmitting unit, and the other path enters the reference unit; a microwave signal entering the transmitting unit is transmitted into the plasma through a fundamental mode rectangular waveguide in the transmitting circuit; the microwave signal entering the reference unit is subjected to flight time compensation through a delay line and then is mixed with a reflected signal received by the receiving unit in a balanced mixer; the calibration unit carries out secondary frequency mixing on the dispersion calibration voltage-time curve signal and the signal obtained after primary frequency mixing of the balanced frequency mixer so as to eliminate dispersion interference; the acquisition card acquires an output signal after secondary frequency mixing of the calibration unit. The system can be integrated with an ion cyclotron resonance antenna, the inherent defects of large attenuation and high dispersion of a long-distance fundamental mode waveguide are overcome, and a high-frequency fundamental mode waveguide through-wall scheme meeting ultrahigh vacuum performance index requirements is realized.

The invention provides a laser radar ranging method based on parallel detection, which relates to the technical field of laser radar ranging, and comprises the following steps: generating N lasers with different wavelengths, splitting beams by a beam splitter, separating optical channels with N independent wavelengths by a demultiplexer, performing frequency shift processing, combining N paths of optical signals after frequency shift through a beam combiner, and combining the N paths of optical signals after frequency shift through a beam splitter; generating a beam of composite reference light containing N wavelengths, wherein each wavelength has a specific frequency shift; signal light returned from a target and the composite reference light are jointly input into a coupler for frequency mixing so as to generate an optical beat frequency signal, and operation processing is performed to calculate the target distance and the target radial speed corresponding to each wavelength. According to the laser radar ranging method provided by the invention, parallel detection of the laser radar can be realized, beat frequency signals corresponding to a plurality of different wavelengths can be distinguished only by integrating a group of detectors, a cross-group amplifier and an analog-to-digital converter, the cost is greatly reduced, and the complexity of the system is reduced.

The invention belongs to the induction type oil abrasive dust sensor technology, and particularly discloses a non-ferromagnetic oil abrasive dust high signal-to-noise ratio induction type detection method and system, and the method comprises the following steps: a microcontroller carries out the control, and sends an instruction to two waveform generation chips through the microcontroller; dual-signal generation: generating two waveform and phase-adjustable periodic signals based on two waveform generation chips; the square wave frequency mixing is used for introducing a square wave as a parameter control signal to carry out frequency mixing operation; and frequency mixing difference adjustment: the optimal signal-to-noise ratio of different non-ferromagnetic chip signals is obtained by adjusting the frequency mixing difference. The frequency mixing difference between the induction signal and the reference signal can be accurately controlled, especially for non-ferromagnetic chips, different frequency mixing differences are adopted to improve the chip signal-to-noise ratio, meanwhile, square waves are introduced to serve as the reference signal to improve the chip signal amplitude, the phase shift process is simplified, the stability of the circuit is improved, and reliable data are provided for subsequent chip signals.

The invention discloses a low-cost broadband direct synthesis type frequency source, belongs to the technical field of radar communication, and mainly solves the problem that a traditional direct synthesis type frequency source cannot simultaneously realize low phase noise, short frequency hopping time and low cost. The frequency source comprises a harmonic generation circuit, a power division circuit connected with the harmonic generation circuit, a switch matrix connected with the power division circuit, and a frequency mixing synthesis circuit connected with the switch matrix. Wherein the harmonic generation circuit is used for generating a harmonic signal, the power division circuit is used for dividing the harmonic signal into six paths, and the switch matrix is used for outputting two paths of 12-17GHz signals from the power-divided signals. Compared with the traditional direct synthesis type frequency source, the direct synthesis type frequency source disclosed by the invention has the advantages that one harmonic generator and one switch filter group are omitted, so that the direct synthesis type frequency source disclosed by the invention realizes a low-cost broadband direct synthesis type frequency source.

Disclosed are a receiver interference response modeling method, and a system, based on a temporal convolutional network. Nonlinear characteristics of a receiver are modeled by means of a temporal convolutional network, a temporal convolutional network is trained by using data of a receiver port under a part of typical interference conditions, then a trained model is used for predicting an interference response under another interference condition, and finally, a frequency domain signal of an output end of the receiver is obtained by means of a Fourier transform, and functionality of equivalent modeling of the receiver is achieved. The present invention uses a temporal convolutional network, and effectively solves problems present in an existing modeling method by means of expanding a receptive field and using causal convolution, accurately fitting nonlinear characteristics caused by filtering and frequency mixing of the signal in a receiver under conditions in which an internal parameter of the receiver is unknown.

A non-contact real-time monitoring system of physiological signs based on millimeter-wave radar includes a millimeter-wave radar and multiple modules for processing radar signals. The millimeter-wave radar is configured to continuously transmit electromagnetic wave signals and simultaneously receive echo signals, perform frequency mixing processing on the echo signals to obtain an intermediate frequency signal, and process the intermediate frequency signal to obtain a radar four-dimensional data matrix. Human body physiological signs are monitored by analyzing body thoracic cavity micro-motion information in signals through the modules; a target echo is processed by adopting a constant false alarm rate detection algorithm, and invalid signals are filtered. A self-adaptive range cell selection algorithm based on short-time stability of respiratory signals is adopted to capture radar echoes reflecting physiological movement. Mixed human body physiological sign signals are processed by using a VMD algorithm, and key parameters in VMD are optimized by using a GWO algorithm.

The invention provides a frequency mixing MEMS piezoelectric loudspeaker and a manufacturing method thereof, the frequency mixing MEMS piezoelectric loudspeaker comprises a plurality of MEMS piezoelectric sound production units, the structure of a vibrating diaphragm of each unit is a cantilever beam structure, a bridge type structure or a periphery reinforcing structure, if the sizes of cavities of all the MEMS piezoelectric sound production units are the same, the structures of the vibrating diaphragms of at least two MEMS piezoelectric sound production units are different, and if the sizes of the cavities of all the MEMS piezoelectric sound production units are the same, the structures of the vibrating diaphragms of all the MEMS piezoelectric sound production units are different. If the size of the cavity of at least one MEMS piezoelectric sound production unit is different from the size of the cavity of the other MEMS piezoelectric sound production unit, the structures of the vibrating diaphragms of the plurality of MEMS piezoelectric sound production units are the same or different, and the sizes of the cavities and the structures of the vibrating diaphragms are related to the resonant frequency of the MEMS piezoelectric sound production units. According to the loudspeaker, the plurality of MEMS piezoelectric sounding units have different diaphragm structures and / or have different cavity sizes, so that the output sound pressure level SPL of the loudspeaker can be improved, and the audio frequency response range is widened.

The invention relates to the technical field of multi-plane light conversion, in particular to a multi-dimensional demultiplexing and frequency mixing system based on an MPLC and an optimization design method of the multi-dimensional demultiplexing and frequency mixing system. The system comprises an input module used for inputting multimode signal light and local oscillation light; the MPLC module is used for realizing unitary transformation of light in any space, comprises N cascaded phase transformation areas and is integrated on the reflecting mirror or the transmitting mirror; the phase transformation regions are phase plates or metasurfaces, and at least one phase transformation region is a metasurface; and the output module is used for receiving the single-mode Gaussian light spots after demultiplexing and frequency mixing. According to the invention, different phases of different wavelengths and different polarization states are regulated and controlled through the metasurface; parallel demultiplexing of wavelengths, polarization and modes in multimode signals can be realized.

The invention discloses a DP-MZM-based reconfigurable mixer with phase shift and image rejection functions, and belongs to the field of microwave photon signal processing. By adjusting an input radio frequency signal and a direct current bias voltage of the DP-MZM1, four different LO frequency doubling and mixing functions can be realized. By controlling the angle alpha between the polarization direction of the polarization analyzer and one axis of the modulator, the phase of the generated signal can be flexibly tuned in the range of 0-360 degrees. When combined with the optical frequency comb, the multi-channel multi-band frequency conversion system can be expanded into a multi-channel multi-band frequency conversion system with independent phase tuning capability by utilizing the channel switching and frequency slot selection functions of the wavelength selection switch, and parallel output of various frequency mixing results can be realized. By adjusting the phase difference between the two-channel output signals, I / Q mixing, double-balanced mixing and image rejection mixing can be configured. The scheme is not influenced by direct current bias drift, the system complexity is reduced, and the frequency conversion efficiency is improved.

The invention discloses a gesture recognition method and system based on an active acoustic sensing field, and the method comprises the steps: transmitting a frequency modulation continuous wave through a loudspeaker on head-mounted equipment, and receiving an echo signal reflected by the hand of a wearer through a microphone on the head-mounted equipment; performing frequency mixing, low-pass filtering and analog-to-digital conversion on the echo signal to obtain a digital baseband signal; performing range correction and noise reduction processing on the digital baseband signal to obtain a hand echo signal; inputting a hand echo signal into the multi-scale time sequence encoder, and capturing long time sequence dependence to obtain multi-scale spatial-temporal characteristics; performing trajectory tracking on the multi-scale spatial-temporal features by the hand key point regression branches to obtain hand key point features; inputting the hand key point features and the multi-scale spatial-temporal features into the gesture recognition branch to obtain a gesture recognition result; according to the method, multipath interference and spatial fuzziness in the acoustic sensing process can be overcome, and high-precision and fine-grained gesture recognition is realized.

The invention discloses an unmanned aerial vehicle target active detection method and system based on a millimeter wave radar, and relates to the technical field of unmanned aerial vehicle detection, and the method comprises the steps: carrying out the frequency mixing of an obtained emission frequency modulation continuous wave signal and an echo signal, and obtaining an intermediate frequency signal; performing fast Fourier transform on the intermediate frequency signal to obtain distance information of the target unmanned aerial vehicle; acquiring a plurality of Chirp signals based on the echo signals; based on the phase difference among the plurality of Chirp signals, calculating to obtain the speed information of the target unmanned aerial vehicle; performing angle estimation on the echo signal to obtain angle information of the target unmanned aerial vehicle; integrating the distance information, the speed information and the angle information of the target unmanned aerial vehicle to obtain motion parameters of the target unmanned aerial vehicle; and transmitting the motion parameters of the target unmanned aerial vehicle to a flight control system or other data receiving equipment of the unmanned aerial vehicle. The detection capability and the tracking effect of the unmanned aerial vehicle target can be improved, and the operation safety of the unmanned aerial vehicle is effectively guaranteed.

The invention discloses a planetary atmospheric trace gas spectrum telemetering and in-situ fusion detection system and method, and belongs to the technical field of deep space exploration. The detection system has a telemetering mode and an in-situ detection mode, and comprises a telescope module, a laser light source module, a heterodyne spectrum telemetering module, an in-situ absorption spectrum module, a gas sampling and enriching module and a signal acquisition, processing and control module. In the on-orbit stage, a heterodyne spectrum telemetering module is adopted, and a laser light source and sunlight signals are subjected to frequency mixing for atmospheric component telemetering; and after the detector enters an atmospheric descending section, the in-situ absorption spectrum module performs in-situ absorption spectrum measurement by utilizing the detection light of the same laser light source. By performing space-time fusion and joint inversion on the data acquired in the two modes, coherent detection from large-range general survey to fixed-point detailed survey is realized, the problems of load separation of telemetering and in-situ detection and difficulty in data fusion are solved, and the detection efficiency, the data consistency and the integration level of the system are greatly improved.

The invention relates to a low-noise high-precision pressure measuring circuit which comprises a bridge type sensor, an alternating-current excitation signal source, a phase-sensitive detector, a low-pass filter, a reference signal source and a signal conditioning amplifier. The alternating current excitation signal source modulates a differential voltage signal generated by the bridge type sensor to a high-frequency alternating current excitation signal generated by the alternating current excitation signal source to obtain a high-frequency pressure signal; the high-frequency pressure signal is amplified by the signal conditioning amplifier to form a modulated signal; the phase-sensitive detector performs frequency mixing on the modulated signal and a reference signal generated by a reference signal source to obtain a frequency mixing signal; the frequency mixing signal is filtered by a low-pass filter to form a direct-current voltage signal for pressure measurement; the reference signal generated by the reference signal source and the high-frequency AC excitation signal generated by the AC excitation signal source have the same frequency. According to the circuit, signals are modulated to a high-frequency area with low noise energy to be processed by adopting alternating-current excitation and coherent detection technologies, the signals and noise are effectively separated, and extremely high measurement resolution and precision are achieved.

The invention belongs to the technical field of full-duplex communication, and particularly discloses a high-isolation full-duplex transceiver system and a control method.The system comprises a transmitting module, a receiving module and a full-duplex baseband module, the transmitting module comprises a power amplifier module and a first oscillator, the power amplifier module is connected with the full-duplex baseband module, and the first oscillator is connected with the receiving module; an intermediate frequency signal transmitted by the full duplex baseband module enters the power amplifier module, is mixed with a signal with a frequency f4 generated by the first oscillator, and is up-converted to a frequency f3; the receiving module comprises a second oscillator and a low-noise amplifier module, the second oscillator is connected with the low-noise amplifier module, a receiving antenna of the receiving module receives the signal and inputs the signal into the low-noise amplifier module for frequency mixing with the signal of the second oscillator, the signal is down-converted to frequency f2, and the signal enters the full-duplex baseband module for data processing. By adopting the technical scheme, based on each module, the influence of self-interference leaked by a transmitting link on a receiving link is completely avoided, and the design complexity of any system is not increased.

The utility model discloses a miniaturized image rejection frequency mixing circuit, which comprises two passive double-balanced frequency mixers, a local oscillator bridge, a phase shift circuit and a power divider, the first input ends of the first passive double-balanced mixer and the second passive double-balanced mixer are connected with an external antenna; the second input end of the first passive double-balanced mixer is connected with the first output end of the local oscillator bridge, the second input end of the second passive double-balanced mixer is connected with the second output end of the local oscillator bridge, and the output end of the first passive double-balanced mixer is connected with the input end of the phase shift circuit. The output end of the second passive double-balanced mixer is connected with the second input end of the power divider; the isolation end of the local oscillator bridge is connected with the load resistor, and the input end of the local oscillator bridge is connected with the frequency source; the output end of the phase shift circuit is connected with the first input end of the power divider, and the output end of the power divider is connected with an external circuit. According to the utility model, the size of the image rejection mixer can be obviously reduced, and miniaturization design of a radar receiver is facilitated.

The embodiment of the invention discloses a radar ranging method and system based on coherent internal difference and microwave depth phase modulation. A signal source is utilized to generate a radio frequency signal, the radio frequency signal is divided into two paths, and one path is sent; performing frequency mixing on the other path of radio frequency signal and the receiving signal to obtain a frequency mixing signal; preprocessing the frequency mixing signal, performing error correction after preprocessing to obtain a frequency mixing signal after error correction, and calculating amplitude frequency spectrum information; setting a target function for expressing the difference between the theoretical model of the numerical features of the ranging parameters and the predicted values of the ranging parameters; taking the minimization of the target function as a learning target, carrying out multiple times of iterative fitting on the distance measurement parameters until the target function converges, and obtaining the distance measurement parameters when the target function converges; and calculating distance information and displacement information of the target by using the distance measurement parameters. According to the invention, frequency modulation is carried out on a single frequency source, and high-precision distance measurement and displacement detection can be realized through a simple transmit-receive antenna and amplification, frequency mixing, filtering and post-processing algorithms.

The invention relates to the technical field of signal generation, and discloses a signal generation system and method, and the system comprises a first signal generation module; the second signal generation module comprises an analog signal generation unit and a signal copying unit; the signal mixing module comprises an analog frequency mixing unit, a digital frequency mixing unit and a signal switching unit; the output end of the analog signal generation unit is connected with the input end of the analog frequency mixing unit; the first end of the signal copying unit is connected with the clock signal output end of the analog signal generating unit, the second end is connected with the mixing input end of the analog signal generating unit, and the third end is connected with the first end of the signal switching unit; the second end of the signal switching unit is connected with the output end of the analog frequency mixing unit, and the third end is connected with the input end of the digital frequency mixing unit. Therefore, a direct digital frequency synthesizer in the analog signal generation unit is calibrated when the clock signal is switched to, and spurious signals are eliminated based on a calibration result when the clock signal is switched to the analog local oscillator signal.

The invention discloses a calibration method for receiving a digital phased-array antenna, which comprises the following steps of: generating one path of signal as a reference signal by adopting a sampling DBF unit FPGA (Field Programmable Gate Array) itself, opening antenna array element channel signals in a beam pointing normal direction in a far-field test environment, and performing synchronous frequency mixing on each array element channel signal and the reference signal, and finally, the relative phase difference Phase of each antenna array element channel is obtained. According to the method, the complexity of the radio frequency assembly is reduced, and the product cost is reduced; regional calibration can be carried out on a large-scale receiving digital phased-array antenna, and the distance requirement of far-field calibration is reduced.

The embodiment of the invention discloses a tensor kernel-based mixing filtering method, device and equipment and a medium, and the method comprises the steps: determining a weight coefficient matrix of a first filter according to a function relation between an output signal and an input signal of the first filter, the weight coefficient matrix is used for converting an original one-dimensional convolution operation corresponding to the first filter into a matrix multiplication operation of a weight coefficient and an input signal, and the stride of the original one-dimensional convolution operation corresponding to the first filter is greater than 1; matrix vector point multiplication operation is carried out on local oscillator signal matrixes corresponding to all paths of local oscillator signals through the weight coefficient matrix, and the obtained matrix serves as a fusion coefficient matrix after frequency mixing and filtering fusion; and carrying out matrix multiplication operation on an input signal matrix corresponding to an input signal to be processed and the fusion coefficient matrix so as to carry out filtering processing on the input signal. By adopting the technical scheme, the throughput of data processing is improved, and memory occupation and power consumption are reduced.

The invention provides a compact medium / low-voltage AC / DC solid-state transformer based on an MMC midpoint embedded sub-module. The compact medium / low-voltage AC / DC solid-state transformer comprises a low-voltage DC port, a three-phase DC / AC converter, a three-phase circuit topology and a medium-voltage AC port, the three-phase circuit topology comprises three same single-phase lines, and each single-phase line comprises an upper bridge arm, an upper bridge arm inductor, an embedded module, a lower bridge arm and a lower bridge arm inductor. The embedded module comprises a first switching tube, a second switching tube, a third switching tube, a fourth switching tube, a fifth switching tube, a sixth switching tube, a direct-current capacitor and a high-frequency transformer. According to the solid-state transformer, by introducing one embedded module, the number of high-frequency transformers of a traditional solid-state transformer is reduced to only one high-frequency transformer for each phase, and the size of the solid-state transformer is greatly reduced; as the upper and lower bridge arms can generate high-frequency voltage pulses, high-frequency pulse voltage generated by the embedded module can be eliminated. Therefore, the high-frequency pulse voltage output by the embedded module does not deteriorate the circulating current of the bridge arm.

The invention provides a loudspeaker online monitoring system and a public broadcasting system. The system comprises an upper computer, a detection control device, a power amplifier and a detection terminal matched with a loudspeaker, the first end of the detection control device is connected with the input end of the power amplifier; the second end of the detection control device and the output end of the power amplifier are connected with the input end of each detection terminal; the detection control device is used for carrying out frequency mixing on the audio signal and the superaudio signal and sending a frequency mixing signal to the power amplifier; the power amplifier is used for amplifying the received frequency mixing signal and sending the frequency mixing amplified signal to each detection terminal; the detection terminal is used for sampling the power amplifier circuit and the loudspeaker loop, and when the sampling voltage of the power amplifier circuit and the sampling current of the loudspeaker loop comprise superaudio data and the superaudio data are within a preset voltage range, the power amplifier circuit and the loudspeaker loop are judged to work normally; according to the invention, one-to-one detection of the loudspeakers can be realized, and the detection precision of the working states of the loudspeakers can be improved.

A spectral linewidth adjusting method includes: adjusting a timing of a first trigger signal for amplifying and converting a portion of a first pulse laser beam to a second pulse laser beam and / or a timing of a second trigger signal for amplifying and converting a portion of second continuous light to a third pulse laser beam and adjusting a spectrum of a fourth pulse laser beam obtained by performing sum-frequency mixing of the second and third pulse laser beams to a first spectrum in a non-Gaussian shape; and modulating a wavelength of the second continuous light within time corresponding to one pulse of the third pulse laser beam and adjusting the spectrum of the fourth pulse laser beam to a second spectrum having a spectral linewidth wider than the first spectrum through generation of a modulation signal for supplying the modulation signal to an optical phase modulator.

The invention discloses an in-vitro liquid level measurement method and device based on millimeter wave radar and a medium, and relates to the technical field of liquid level measurement, and the method comprises the steps: collecting geometric parameters of a container, building a container coordinate system, and forming static background data; the millimeter wave radar array is controlled to radiate millimeter wave signals in sequence, a receiving channel receives reflection echoes, amplification, frequency mixing, filtering and sampling processing are carried out, and array time sequence data are obtained; according to the array time sequence data, generating a distance direction frequency spectrum data set, combining static background data to carry out background deduction, executing an incident direction estimation algorithm, obtaining scattering point cloud under a container coordinate system, and generating a liquid level two-dimensional contour; based on the two-dimensional contour of the liquid level and the geometric parameters of the container, effective bottom surface grids are screened, the estimated value of the liquid volume in the container is obtained and converted into the equivalent liquid level height, and the final liquid level height is obtained. The two-dimensional fluctuation form of the liquid level is finely described, and the liquid volume and liquid level height measurement precision is improved.

The invention discloses a digital down-conversion and anti-mirror-interference method for the Internet of Things, and the method comprises the following steps: S1, constructing a receiving path, carrying out the down-conversion of a radio-frequency signal, and carrying out the analog-to-digital conversion of the radio-frequency signal into a low-intermediate-frequency I / Q orthogonal digital signal; s2, inputting the I / Q signal into a notch filter, suppressing harmonic interference of a crystal oscillator, and outputting an interference weakening signal; s3, looking up the table to generate an orthogonal local oscillator signal; s4, performing compound frequency mixing on the filtered I / Q signal and a local oscillator signal; s5, inputting the frequency mixing signal into a mirror image rejection module, and executing weighting operation to filter mirror image interference; s6, inputting the signal into a low-pass filter, suppressing sideband and mirror image residue, and outputting a target baseband signal; s7, performing normalization and compression processing on the signals; and S8, inputting into a post-stage processing module, and dynamically adjusting parameters according to feedback to enhance the anti-interference capability. According to the method, a low-power-consumption digital down-conversion link is constructed, image rejection and a self-adaptive mechanism are fused, and robust receiving processing of interference is achieved.

The invention relates to the technical field of laser ultrasound, and particularly discloses a multi-dominant-frequency laser ultrasonic holographic system and a design method.The system comprises a laser and a laser beam adjusting module used for receiving and adjusting laser beams, the laser beam adjusting module comprises a beam expanding lens and a collimating lens which are coaxially arranged, the beam expanding lens is used for adjusting the diameter of the laser beams, and the collimating lens is used for adjusting the diameter of the laser beams; the collimating mirror is used for collimating the laser beams so that the laser beams are kept parallel and focused; the frequency mixing ultrasonic holographic lens comprises a light focusing layer, a sound restraint layer, a light absorption layer, a sound matching layer and a sound holographic layer which are stacked in sequence, and the frequency mixing ultrasonic holographic lens is used for receiving the laser beams passing through the laser beam adjusting module so as to generate multiple stable single or multiple focusing ultrasonic sound fields with different preset frequencies in a time-sharing or simultaneous manner; and the focusing focus position and power can be adjusted, so that the device can be used for ultrasonic control and driving, ultrasonic detection imaging, low-power ultrasonic stimulation or power ultrasonic treatment and the like.

The invention relates to a method for rapidly measuring the resonant frequency of a resonant cavity based on frequency spectrum polynomial fitting, and belongs to the technical field of acoustic / optical measurement. The objective of the invention is to solve the problems of tedious steps, low efficiency, long time, poor stability and the like of a resonant cavity or resonant photoacoustic cavity resonant frequency measurement method. According to the method, the frequency spectrum of the resonant cavity is obtained through frequency mixing excitation, the frequency is obtained after curve fitting is conducted on frequency spectrum data points through a frequency spectrum polynomial fitting algorithm, and then resonant frequency measurement of the resonant cavity is achieved. According to the method, the measurement time of the resonant frequency of the resonant cavity is remarkably shortened, the measurement steps are simplified, and the measurement precision is improved; meanwhile, the resonance frequency is solved through frequency spectrum polynomial fitting, data noise interference can be effectively reduced, and the method has higher robustness. All frequency signals within the resonant frequency drift range are transmitted at a time through frequency mixing excitation, one-by-one scanning is not needed, and therefore the method has the advantages of being good in real-time performance, high in response speed, high in precision and the like, and is suitable for rapid frequency calibration and real-time monitoring in the fields of acoustic resonators, resonant photoacoustic spectra and the like. And a novel method for measuring the resonant frequency is provided for the fields of high-sensitivity resonance photoacoustic spectroscopy, acoustic trace gas detection and the like.

The utility model discloses a real-time vector detection device based on a radio frequency signal short-wave antenna tuner, which comprises a radio frequency signal sampling module, an AGC, an AD and an FPGA, the sampling input end of the radio frequency signal sampling module is connected with a radio frequency path, and the output end of the radio frequency signal sampling module is provided with a forward signal end and a reverse signal end and is connected to the AGC; the AGC can perform gain attenuation processing on an input forward signal and an input reverse signal, an output end of the AGC is provided with a forward signal end and a reverse signal end which are respectively connected to a sampling input end of the AD, the AD is a dual-channel over-sampling analog-to-digital conversion module, an output end of the AD is connected with the FPGA, an input clock of the FPGA is 100MHz, the DDS is realized by adopting an IP core design, the FPGA can realize sampling, calculation and frequency mixing, and the FPGA is connected with the FPGA. And the matching network is controlled to realize tuning and system protection or alarm according to the calculated impedance value and standing-wave ratio. According to the utility model, the hardware circuit is simplified, the power standing-wave ratio condition of the access can be detected in real time, the detection efficiency is improved, the use is convenient, and the detection is efficient and accurate.

The invention discloses a signal reading system and method for superconducting microwave multiplexing device detection, and belongs to the field of superconducting microwave multiplexing device detection, and the system comprises a server which can issue a detection configuration instruction to a signal board, receive and return detection data, operate detection software, execute spectrum analysis and data analysis, and generate a detection result; the signal board is provided with a circuit containing a programmable logic device, and the circuit can output accurate intermediate frequency signals and excitation current signals according to instructions of the server, processes output signals of the detected superconducting microwave multiplexing devices mixed by the frequency mixing board through a critical sampling filter bank algorithm to obtain detection data, and transmits the detection data back to the server; and the frequency mixing plate can perform up-conversion on the intermediate frequency signal generated by the signal plate to radio frequency to form a radio frequency detection signal, output the radio frequency detection signal to each detected superconducting microwave multiplexing device, perform down-conversion on the radio frequency response signal returned from each superconducting microwave multiplexing device to intermediate frequency, and output the radio frequency response signal to the signal plate. The system can detect the quality of the device with low computing resources.

The invention provides a phase noise measurement method and device, electronic equipment and a storage medium, and belongs to the technical field of test.The method comprises the steps that a signal to be tested is divided into a first signal and a second signal, frequency mixing processing is conducted on the first signal and a first reference signal, and a first real number signal is obtained; performing frequency mixing processing on the second path of signal and the second reference signal to obtain a second path of real number signal; splicing the first path of real number signal and the second path of real number signal to obtain a complex number signal; performing Fourier transform on the complex signal to obtain a frequency domain complex signal; separating a first frequency domain complex signal and a second frequency domain complex signal from the frequency domain complex signal; and performing cross-correlation operation on the first frequency domain complex signal and the second frequency domain complex signal to obtain a phase noise measurement result of the signal to be measured. According to the invention, Fourier transform is carried out on the complex signal, so that the data processing flow is simplified, the measurement efficiency is improved, and the cost is reduced.