73 results about "Digital down conversion" patented technology

The invention relates to a low-orbit satellite short burst signal high-precision capturing method and device, equipment and a medium. The method comprises the following steps: sequentially carrying out digital down-conversion and L-time signal pseudo code rate down-sampling on a low earth orbit satellite short burst signal sequence sampled by an ADC (Analog to Digital Converter) to obtain a down-sampled signal sequence; performing pre-accumulation processing on the down-sampling signals of every adjacent L points in the down-sampling signal sequence, and performing coarse capture on the pre-accumulated signal sequence by adopting a PMF-FFT algorithm to obtain a coarse pseudo code phase and a coarse frequency offset value; and performing serial code phase search on the down-sampling signal sequence based on the coarse pseudo code phase and the coarse frequency offset value, optimizing to obtain a fine pseudo code phase, and optimizing the estimation precision of the coarse frequency offset value according to the fine pseudo code phase and a frequency offset estimation algorithm based on a phase relation to obtain a fine frequency offset value. By adopting the method, the acquisition precision and speed of the short burst signal of the low-orbit satellite can be improved.

The invention particularly relates to a method for converting pseudo code capture into tracking phase compensation under clock frequency offset. The method comprises the steps of band-pass sampling and digital down-conversion, local pseudo code sequence generation, twice pseudo code capture and phase compensation. Selecting a sampling frequency and processing a signal through a band-pass sampling theorem, and generating a local pseudo code based on a Gold code; a PMF-FFT method of a mobile pseudo code is adopted to complete first-time pseudo code capture, a multiplexing capture module executes second-time full-range capture, and pseudo code phase offset is accurately calculated; and finally, adjusting the local pseudo code phase through the total phase compensation value, so that the phase difference between the input signal and the local pseudo code is controlled within a half chip. According to the method, hardware cost does not need to be increased, the problem of inaccurate phase compensation under clock frequency offset, large frequency offset and low carrier-to-noise ratio scenes is effectively solved, it is guaranteed that pseudo code capture is smoothly converted into tracking, and the tracking reliability of a receiver is improved.

The application discloses a handheld spectrum analyzer real-time spectrum signal processing system and processing method, the system comprises a pre-processing unit, an ADC unit, an FPGA and an ARM which are connected in sequence, the FPGA comprises a digital down conversion unit, a multi-rate decimation filter unit, a real-time FFT operation unit and a real-time detection unit which are connected in sequence, and a grid mapping unit, a vector connection unit and a fluorescence statistical unit which are connected with the real-time FFT operation unit in sequence, the ARM comprises a real-time spectrum diagram and waterfall diagram unit which is connected with the real-time detection unit, and a fluorescence display unit which is connected with the fluorescence statistical unit. The application adopts parallel frame real-time detection and vector connection-based digital fluorescence statistical method to compress multiple spectrum data, reduces the requirement of a large number of spectrum data on screen refreshing, adopts vector connection to make fluorescence statistics, so that the measured signal is easier to distinguish, and the application meets the test requirement of a handheld instrument.

The invention provides a vehicle-mounted SDR monitoring method and device for mobile monitoring of an urban electromagnetic environment, and the method comprises the steps: receiving and down-converting a radio frequency signal through a radio frequency front-end module, carrying out the analog-to-digital conversion and digital down-conversion of a signal processing module, and carrying out the spectrum analysis through a main control and analysis module; when the monitoring bandwidth exceeds the single sampling capability of hardware, a step tuning strategy is adopted to carry out segmented scanning and frequency spectrum splicing; performing standardization processing on the data through a power calibration model, and finally uploading the standardized spectrum data through an MQTT protocol; according to the invention, a reconfigurable SDR platform is adopted, and step tuning, power calibration and lightweight transmission mechanisms are combined, so that the technical problems of limited bandwidth, hardware rigidity, unreliable data transmission, uncomparable measurement results and the like of traditional monitoring equipment are solved, and broadband, high-precision and high-efficiency urban electromagnetic environment mobile monitoring is realized.

The invention provides a WiFi network digital down-conversion system which comprises a multi-phase mixer and a resampling filter. The multi-phase mixer is used for converting a high-speed digital band-pass signal into a low-speed mode so as to realize digital down-conversion (DDC) on an FPGA (Field Programmable Gate Array) platform; and the resampling filter is used for reducing the sampling rate and removing unwanted frequency spectrum components to generate a complex baseband frequency spectrum. The multi-phase mixer PM of the present invention employs a parallel coordinate rotation digital computer (CORDIC) processor and a low pass filter array to reduce high speed data rates while minimizing resource utilization. The resampling filter comprises a cascade integral combination (CIC) filter and a multi-channel pulse finite impulse response (FIR) filter, optimal hardware cost is achieved, a floating point data type is converted into a fixed point data type, and resources are remarkably saved.

The application relates to the technical field of data processing, and discloses a receiving multi-channel phase fast calibration compensation method, which comprises the following steps: sending original sampled data into a digital down-conversion module, sending filtered data into a peak value searching module, calculating a signal phase, calculating corresponding sine and cosine values, and outputting calibrated data after the down-converted data are multiplied with the sine and cosine values calculated in step S4 through a phase compensation module; the receiving multi-channel phase fast calibration compensation method can perform real-time phase calibration compensation, can perform phase calibration compensation on multiple different frequency points respectively, and greatly improves the calibration precision and the calibrated performance; the method can enable a large phased array system to be quickly deployed, greatly saves the time spent in calibrating the phase, can also reduce the uncertainty caused by human measurement errors, and greatly improves the stability of the system.

The invention particularly relates to a multi-dimensional suppressing interference rapid interception response signal processing method, which comprises the following steps of: setting energy and frequency detection after echo sampling, setting energy and frequency detection after digital down-conversion, setting signal feature detection after pulse compression and moving target indication, and setting statistical detection after CFAR (Constant False Alarm Rate) detection. Signal feature detection is set after moving target detection and SAR imaging. And based on the score of each detection module, control enabling of different priorities on the anti-interference function of the system, including an immediate dimension, a short-time dimension and a long-time dimension, is generated, so that the aim of rapidness is fulfilled. According to the method, the suppression interference is accurately and quickly identified in combination with the judgment standards of multiple dimensions, the anti-interference response is carried out at the fastest speed, and the anti-interference response is carried out at the fastest speed. The application can be well embedded into a conventional radar signal processing system, has the characteristics of strong universality, good real-time performance and high accuracy, and can be widely applied to the field of digital signal processing products.

The invention discloses a terahertz frequency modulation continuous wave radar signal processing system and method based on an FPGA. The system comprises an A / D acquisition control module, a digital down-conversion module, a fast two-dimensional Fourier transform module, a non-coherent accumulation module and a constant false alarm detection module. The method comprises the following steps that: the A / D acquisition control module samples an analog echo signal; the digital down-conversion module performs digital down-conversion processing on the sampling signal to obtain baseband echo I and Q data; the fast two-dimensional Fourier transform module is used for carrying out FFT (Fast Fourier Transform) on baseband echo I and Q data to obtain a range profile of a target, and the non-coherent accumulation module is used for carrying out amplitude accumulation and averaging on a plurality of target range profiles in different periods in the same wave beam; and the constant false alarm detection module compares and judges the signal amplitude of the detection unit with a set threshold to obtain a false alarm detection result. The method has the advantages of being high in real-time performance, high in reliability, simple in design, high in adaptive capacity and wide in application range.

This invention addresses the problem that the direct zeroing method used in existing satellite navigation signal processing frequency domain FFT notch filtering easily leads to power loss near interference frequencies, affecting signal integrity. It proposes a narrowband interference suppression system and method for BeiDou navigation. The narrowband interference suppression system includes a BeiDou RF front-end module, a high-speed ADC sampling module, a digital down-conversion (DDC) module, a signal distributor and buffer module, an interference detection and parameter estimation unit, an interference suppression execution unit, a baseband correlation and demodulation module, and a navigation and positioning result output module. A cascaded array of IIR notch filters is constructed using a cascaded array module. A steep transition band is achieved through small-order serial units, and the stopband width of the notch filters can be flexibly adjusted via a convergence factor. This enables precise suppression of extremely narrow stopband interference at different bandwidths, filtering out signals only at interference frequencies, effectively avoiding impact on surrounding useful BeiDou signals and preventing spectrum leakage.

The invention discloses a voice signal silencing device based on joint detection. A received intermediate frequency voice signal is subjected to analog-to-digital conversion and digital down-conversion through an AD module and a down-conversion module; after digital automatic gain control is completed by the AGC module, the voice signal is divided into two paths; the carrier detection processing module carries out carrier detection processing on one path of voice signals to obtain power spectrum characteristics; the voice squelch detection module demodulates the other path of voice signal, on one hand, demodulated voice is output when the squelch gate is in an open state, and on the other hand, voice feature detection processing is performed on the demodulated voice to obtain voice features; and the joint judgment module performs joint judgment on the power spectrum characteristics and the voice characteristics calculated by the carrier wave squelch detection module and the voice squelch detection module, and controls the opening and closing states of a squelch door. According to the invention, the carrier squelch technology and the voice squelch technology are jointly used, so that the false alarm probability and the missed alarm probability are effectively reduced.

The application provides a general radar array element level multi-target simulation method. After target echo signals received by a radar array surface are converted by an analog-to-digital converter, the target echo signals are usually digital intermediate frequency echo signals. The application can simultaneously simulate digital intermediate frequency signals of multiple targets under the condition that a radar array front end or an external test environment is not provided, and the digital intermediate frequency signals are subjected to digital down-conversion processing to obtain baseband signals. The baseband signals are multiplied by a steering vector of the targets on different array elements to obtain radar array element level multi-target simulation signals. The number of targets, amplitudes, angles, distances, speeds and array element information can be parameterized and configured, the verification and development efficiency of subsequent algorithms is greatly improved, the research and development cost is reduced, and the application has the characteristics of strong universality, high flexibility, fast development efficiency and wide adaptation to scenarios.

The application discloses a spectrum analyzer-based amplitude compensation method and device. The method comprises the following steps: before frequency sweeping starts, determining the starting frequency, stopping frequency and calibration frequency step of the current scanning frequency range, and determining the corresponding shift bit number according to the calibration frequency step, wherein the calibration frequency step is a power of 2; generating calibration data of a plurality of calibration points according to the starting frequency, stopping frequency and calibration frequency step, and storing the calibration data in a storage space accessible by an FPGA in the order of corresponding frequencies; obtaining the frequency value corresponding to the current data during frequency sweeping, and determining the calibration data index according to the frequency value corresponding to the current data and the calibration frequency step according to the upward rounding rule; reading the corresponding calibration data according to the calibration data index; and performing amplitude compensation on the current data by using the calibration data after digital down-conversion and before decimation filtering. The method can reduce the calibration data storage amount and FPGA operation resource consumption, and improve the real-time amplitude compensation accuracy during frequency sweeping of the spectrum analyzer.

This invention provides a broadband signal analyzer, comprising: at least one superheterodyne frequency conversion receiving unit, at least one filtering unit, an ADC, a digital down-conversion and decimation filtering unit, an adaptive filtering unit, a data processing and display unit, and a scan controller, connected in sequence; the superheterodyne frequency conversion receiving unit includes: an attenuator, a mixer, and a local oscillator signal, the attenuator, mixer, and filtering unit being connected in sequence, the output terminal of the local oscillator signal being connected to the input terminal of the mixer, the input terminal of the local oscillator signal being connected to the output terminal of the scan controller, and the input terminal of the scan controller being connected to the output terminal of the ADC. This invention overcomes the problems of high filter order and excessive processing resource consumption caused by existing broadband signal in-band flatness compensation methods.

The invention provides a data processing device, which belongs to the technical field of wireless communication, and comprises an FPGA (Field Programmable Gate Array) chip and a data memory for storing air interface IQ (Intelligence Quotient) data, the FPGA chip further comprises a storage interface module; the frequency band digital down-conversion module is used for performing sampling rate conversion on the digital signal input into the FPGA chip to obtain air interface IQ data and storing the air interface IQ data to the data memory; the frequency point digital down-conversion module is used for responding to the starting instruction of the central processing unit, extracting target air interface IQ data according to pre-configured data reading parameters, and performing sampling rate recovery on the target air interface IQ data to obtain output IQ data; and the post-stage processing module is used for processing the output IQ data and returning a processing result to the central processing unit. On the whole, on the basis of a collaborative architecture combining FPGA hardware acceleration and CPU non-real-time scheduling, multi-system multi-cell data unified storage and dynamic processing which are flexible in expansion and easy to maintain are supported.

The invention discloses a method for realizing digital signal processing of a VOR receiver based on an FPGA (Field Programmable Gate Array) technology, which relates to the technical field of radio navigation and digital signal processing and comprises the following steps of: constructing a VOR full-digital simulation signal source, and simulating signal input in a VOR system; performing digital down-conversion and filtering processing on the received radio frequency signal, and separating a variable phase signal and a reference phase signal through a digital filter; calculating a phase difference by adopting a zero-cross detection method; all the modules are integrated into an FPGA system, and performance testing is carried out. According to the invention, not only can the angle measurement precision, real-time performance and anti-interference capability of the VOR receiver be improved, but also the defects of large temperature drift and large size of the traditional analog receiver can be overcome, the characteristics of reconfigurability and parallel processing of the FPGA are utilized, the requirements of miniaturization and high reliability of modern aviation navigation equipment are met, the upgrading and updating of the full-digital VOR technology in the aviation field are promoted, and the application prospect is wide. And powerful technical support is provided for safe aviation flight.

This invention relates to the field of communication technology, specifically to a frequency offset estimation method based on compressed sensing and frequency doubling joint estimation. The method includes the following steps: S1, establishing a sparse representation model of the signal frequency offset, constructing a sparse dictionary of the signal frequency offset matching the frequency offset characteristics of short-time burst signals based on the sparse representation model, performing a coarse frequency offset estimation using a compressed sensing algorithm, and outputting a coarse frequency offset estimate; S2: based on the coarse frequency offset estimate obtained in step S1, performing digital down-conversion (DDC) processing on the received short-time burst signal to obtain a baseband signal that eliminates the principal components of the coarse frequency offset estimate and retains only the residual small frequency offset; S3: performing a frequency doubling joint estimation on the baseband signal obtained in step S2 using the four-fold relationship of the signal frequency offset to achieve a fine estimation of the frequency offset of the short-time burst signal, and outputting the final accurate frequency offset estimate. This invention solves the technical problems of high sample size requirements and lack of effective connection between coarse and fine estimation in short-time burst signal frequency offset estimation.

The invention discloses a phase noise measurement method and system based on a frequency spectrograph, and relates to the technical field of communication measurement instruments and meters, and the method comprises the steps: obtaining ADC data, carrying out the digital down-conversion and decimation filtering of the ADC data, obtaining IQ baseband data, carrying out the digital phase demodulation of the IQ baseband data, and obtaining phase change data; performing frequency difference estimation on the phase change data to obtain a frequency difference estimation result, and performing frequency difference compensation on the phase change data to obtain compensated phase change data; extracting the compensated phase change data to obtain phase fluctuation data, and performing FFT (Fast Fourier Transform) operation to obtain phase noise original data; carrying out self frequency mixing operation on the IQ baseband data to obtain amplitude modulation noise original data; and performing spectrum estimation processing on the phase noise original data and the amplitude modulation noise original data, and then performing stray elimination and smoothing processing to obtain a final phase noise measurement value and an amplitude modulation noise measurement value.

The invention discloses an ORU radio frequency gain adjusting system suitable for ORAN equipment. The system comprises a hardware platform, field programmable gate array logic and gain control software running on a main controller. The hardware platform comprises a digital radio frequency unit which is integrated in field programmable gate array logic, comprises a digital up-conversion module, a rest factor reduction module, a digital pre-distortion module and a digital down-conversion module, and provides a digital gain adjustment point; the radio frequency transceiving link comprises a digital-to-analog converter, an analog gain controller and a driving amplifier of the transmitting link; the receiving link comprises a low noise amplifier, a variable gain amplifier and an analog-to-digital converter; and a feedback link ADC; and the power amplifier unit comprises a final power amplifier and a bias control circuit thereof. According to the invention, high-precision and self-adaptive control of downlink (DL) and uplink (UL) gains can be realized, so that performance fluctuation caused by frequency and temperature changes and device batch differences can be compensated.

The invention discloses a multi-modulation system carrier synchronization integrated judging and locking device for satellite-to-ground data transmission, and belongs to the field of satellite-to-ground data transmission. The device comprises an AD conversion module, a digital down-conversion module, a low-pass filtering module, a half-band filter bank module, a digital resampling module, a matched filtering module, a carrier phase tracking module, a carrier phase error calculation module, a timing error calculation module and a carrier synchronization judging and locking module. According to the invention, the carrier synchronization integrated locking judgment function of multiple modulation systems in a satellite-ground high-speed data transmission CCM transmission mode and a VCM transmission mode is realized, the adaptability of the device is improved, and the device is convenient to realize and popularize.

This invention discloses a distributed collaborative observation and data fusion method and system for the FAST core array based on RFSOC, comprising: S1 System initialization: The master node RFSOC generates a global clock, and achieves phase synchronization of multiple boards through SYSREF differential signals, completing a three-level clock tree calibration; S2 Signal acquisition and preprocessing: 3-8GHz radio frequency signals are directly sampled by an ADC and digitally down-converted to baseband signals; S3 Intelligent resource scheduling: Signal types are identified based on an echo state neural network (ESN), and FPGA logic resources are dynamically allocated through an improved ant colony algorithm; S4 Heterogeneous computing acceleration: A 128-channel digital beamforming pipeline is executed on the FPGA; S5 Cross-domain data fusion; S6 Collaborative observation planning; S7 Data output. This invention is applicable to scenarios involving multi-beamforming, cross-regional joint observation, and real-time processing of massive amounts of data, providing key technical support for solving cutting-edge scientific problems such as the origin of fast radio bursts and monitoring black hole activity.

This application relates to a method, apparatus, device, and medium for high-precision acquisition of short burst signals from low-Earth orbit (LEO) satellites. The method includes: sequentially performing digital down-conversion and... L The signal pseudocode rate is doubled for downsampling to obtain a downsampled signal sequence; each adjacent... L The downsampled signal is pre-accumulated, and the PMF-FFT algorithm is used to coarsely acquire the pre-accumulated signal sequence, obtaining coarse pseudo-code phase and coarse frequency offset. Based on the coarse pseudo-code phase and coarse frequency offset, a serial code phase search is performed on the downsampled signal sequence to optimize and obtain a fine pseudo-code phase. Then, based on the fine pseudo-code phase and a frequency offset estimation algorithm based on phase relationships, the estimation accuracy of the coarse frequency offset is optimized to obtain a fine frequency offset. This method can improve the acquisition accuracy and speed of short burst signals from low-Earth orbit satellites.

The application relates to a frequency domain beam synthesis device based on FPGA, and belongs to the field of communication countermeasures. The device comprises a high-speed serial transceiver interface module, a wideband digital down-conversion module, a high-speed sampling point calibration module, a beam coefficient cache module, a high-speed calibration synthesis module, a synchronous signal generation and forwarding module, a high-speed frequency domain inter-board synchronous data exchange module, a high-speed frequency domain intra-board synchronous data exchange module and a high-speed interface module; two different protocols of the high-speed interface share one bank interface, multi-phase parallel wideband frequency domain beam synthesis technology is realized through a frequency domain beam adaptive clipping mode, the wideband beam synthesis function can be completed, the multi-element, super wideband and multi-beam beam synthesis function can be completed by using less FPGA resources, and the generated beam is phase-continuous in the wideband. The device is suitable for the pretreatment of the super long distance super wideband signal reconnaissance and direction finding function, has the advantages of high data processing rate, large signal bandwidth, high calibration precision, high synthesis precision, continuous beam phase and the like.

The invention relates to the technical field of radio communication and digital signal processing, in particular to a short-wave broadband radio signal receiving and channelization processing system, which comprises a broadband digital receiving front end, a short-wave digital receiving rear end, a short-wave digital receiving front end and a short-wave digital receiving rear end, the spectrum analysis and signal detection module is used for performing spectrum analysis on the high-speed digital signals and identifying and positioning all signal sources contained in the high-speed digital signals; the dynamic channelization resource management module is used for calculating and distributing corresponding channelization processing resources in real time; the reconfigurable parallel channelization processing engine is used for performing parallel dynamic digital down-conversion and filtering extraction on the high-speed digital signals so as to extract a plurality of independent narrowband signal data streams; a plurality of independent signals in a broadband spectrum can be adaptively detected and simultaneously received; according to the invention, the problem of frequency offset caused by Doppler effect or medium change is effectively solved, and the complexity of rear-end signal processing is reduced.

The invention discloses a digital down-conversion method based on full digital domain processing, which relates to the technical field of signal processing, and comprises the following steps: down-converting an input digital intermediate frequency signal to a zero intermediate frequency position by adopting a frequency mixing mode according to the input digital intermediate frequency signal; performing multi-stage filtering extraction on the signal after frequency conversion processing; and resampling is carried out, and the sampling rate of the signal is changed to adapt to a subsequent signal processing module. According to the invention, the requirement of any multiple sampling rate conversion at the rear end of equipment can be met.

The invention relates to an FPGA + ADC-based digital down-conversion implementation method, and belongs to the technical field of laser radars. According to the invention, the digital down-conversion algorithm is migrated from the FPGA to the ADC, so that the overall operation power consumption of a chip can be reduced, the layout and wiring difficulty between boards can be reduced, the data processing amount of the FPGA can be reduced, and the resource consumption of the FPGA can be further saved.

The invention relates to the technical field of digital signal processing, and discloses a low-duty-ratio pulse signal frequency spectrum monitoring method and system based on an FPGA, and the method comprises the steps: receiving a frequency spectrum monitoring parameter issued by a system; determining processing parameters of fast Fourier transform (FFT) according to the frequency spectrum monitoring parameters and the characteristics of the front-end receiver; based on the processing parameters, performing digital down-conversion processing on the intermediate frequency digital signal after analog-to-digital conversion to obtain a baseband IQ signal; on each scanning frequency point, performing continuous multiple FFT operations on the baseband IQ signal, and performing maximum holding processing on spectrum data obtained by each FFT operation to obtain final spectrum data of the current scanning frequency point; and after all the scanning frequency points are processed, splicing the final frequency spectrum data of each frequency point to obtain a frequency spectrum monitoring result of a complete scanning bandwidth, and reporting the frequency spectrum monitoring result. According to the method, the problem of missing detection caused by non-synchronization of sampling time and pulse occurrence time in a traditional method is effectively solved.

The application belongs to the field of communication measurement and control, and particularly relates to a measurement and control transponder system and equipment for quickly and reliably capturing a mixed spread spectrum signal, and aims to solve the problem of insufficient system precision and weak reliability. The application comprises a digital down-conversion module for receiving a signal and performing digital down-conversion processing on the signal; a direct spread code capture module for capturing the zero intermediate frequency signal and performing modulation to obtain a spread spectrum signal; a frequency hopping interval division module for dividing the bandwidth of the spread spectrum signal into N parallel frequency hopping intervals according to a frequency hopping pattern; a matched filter module for filtering the signal and performing N-point Fourier operation; a capture decision module for comparing the code phase with a threshold value, and if the threshold value is exceeded, determining that capture is successful; and a synchronization refresh module for performing dynamic refresh through a synchronization refresh algorithm. The application improves the capture speed and reliability of the measurement and control transponder.

The application provides a method for in-phase or anti-phase detection of a target signal, comprising the following steps: S1, setting a detection frequency Fc, wherein the detection frequency Fc is a periodic signal at a sampling rate Fs of the received target signal and can be separated by a low-pass filter; S2, digitally down-converting the target signal to move its frequency to the selected detection frequency Fc; S3, separating the target signal by using a low-pass filter, and selecting the detection frequency Fc as the cutoff frequency of the low-pass filter; and S4, detecting the target signal passing through the low-pass filter in a detection period to determine whether the target signal is in-phase or anti-phase. The method and system can quickly detect the in-phase and anti-phase of the target signal, and are simple and have small calculation amount.

The invention discloses an in-band flatness compensation method and system based on a large-bandwidth spectrum analyzer, and relates to the technical field of signal processing, and the method comprises the following steps: obtaining and optimizing a complex compensation coefficient table corresponding to the in-band frequency response of a radio frequency front-end channel filter through a dynamic inner ring calibration and compensation optimization system; receiving a to-be-measured radio frequency signal, filtering the to-be-measured radio frequency signal through the radio frequency front-end channel filter, and performing analog-to-digital conversion and digital down-conversion processing to form a to-be-measured baseband I / Q data frame; performing windowing and fast Fourier transform on the baseband I / Q data frame to be measured to obtain a frequency spectrum of a signal to be measured; performing frequency domain complex multiplication on the frequency spectrum of the signal to be measured and the corresponding complex compensation coefficient in the compensation coefficient table to obtain a compensated signal frequency spectrum; and performing inverse fast Fourier transform on the compensated signal spectrum, and outputting an I / Q signal. According to the invention, logic resource consumption and errors can be reduced.

The invention provides an ultrasonic knife circuit detection method based on non-ionizing electromagnetic radiation, and belongs to the technical field of medical surgical instrument safety monitoring. The method comprises the following steps: injecting a broadband sweep frequency excitation signal into a sealed shell of the ultrasonic knife to excite an internal circuit to generate electromagnetic response; scattering parameters S11 and S21 are synchronously acquired through a multi-antenna array, and a three-dimensional spectrum tensor is generated through digital down-conversion; inputting the tensor into a lightweight convolutional neural network model, extracting PCB microstructure defect features, and outputting a fault diagnosis and positioning result; a diagnosis result is uploaded to an edge node through a 5G network, and cloud digital twin model synchronization and fault evolution simulation are triggered; and when the fault probability exceeds a dynamic threshold value, a local sound-light alarm is activated, and a structured maintenance work order is automatically generated. According to the invention, non-intrusive, high-precision and intelligent ultrasonic knife circuit state monitoring and predictive maintenance are realized.