50 results about "Quadrature demodulation" patented technology

According to an embodiment, a circuit is proposed for generating rate and quadrature demodulation signals, incorporating unidirectional hysteresis for negative edges. The circuit features a preliminary stage that amplifies the differential sinusoidal signal from gyroscopic proof mass oscillations; a gain stage for boosting this signal with adjustable hysteresis levels; an output stage delivering a full-swing square wave output; and a customizable offset component to deepen the drop in the non-inverting compared to the inverting signal for the third signal's falling edge.

The invention provides an adaptive control method and system for an accelerator klystron, and electronic equipment, and the method comprises the steps: collecting a reverse wave signal in a microwave signal which is generated by an excitation source, is amplified by the klystron, and is inputted to an accelerating tube, and obtaining the current output frequency of the excitation source; performing I / Q orthogonal demodulation on the reverse wave signal to obtain an I / Q signal, and calculating the frequency deviation between the current resonant frequency of the accelerating tube and the current output frequency of the excitation source; and according to the frequency deviation, outputting a frequency control instruction to the excitation source so as to adjust the output frequency of the excitation source, and enabling the current output frequency of the excitation source to track the current resonant frequency of the accelerating tube. By calculating the frequency deviation and directly outputting the control instruction to adjust the output frequency of the excitation source, the technical problems of control object dislocation and response lag existing in a traditional automatic frequency control system are solved.

The invention discloses an optical fiber sensor high-speed demodulation device based on a cascaded Mach-Zehnder interferometer, which adopts a two-stage cascaded Mach-Zehnder interferometer structure, and obtains four-channel output with equal central wavelength intervals by accurately aligning two-stage central wavelengths. And the four-channel signal is utilized to carry out orthogonal demultiplexing on a spectral signal of the optical fiber sensor. In a digital domain, an orthogonal demodulation algorithm for phase demodulation of an optical fiber sensor is provided, and the demodulation speed is only limited by a digital sampling rate. Compared with a traditional spectrum demodulation algorithm, the scheme has the advantages of being high in demodulation speed, wide in working frequency band, easy to implement and the like.

The application discloses a laser phase noise measurement method based on delay self-heterodyne and digital demodulation, and relates to the technical field of laser measurement, and comprises the following contents: after being adjusted by a variable optical attenuator, to-be-measured laser is divided into a frequency shift arm and a delay arm, the frequency shift arm is frequency-shifted by an acousto-optic modulator, the delay arm is delayed by a delay optical fiber, and original electric beat frequency signals are obtained by a balanced photoelectric detector after the two arms are coupled; homologous and synchronous quadrature demodulation is carried out on the original electric beat frequency signals, envelope credibility judgment and abnormal sample repair are combined, and a continuous differential phase sequence is obtained; actual optical time delay is determined according to the beat frequency spectrum characteristics and the continuous differential phase sequence, and a differential phase power spectral density is formed; then, transmission relationship conversion is carried out according to the actual optical time delay, bounded spectrum compensation is implemented on a zero point neighborhood and a low credibility frequency point, and an intrinsic phase noise power spectral density is obtained. The application can improve the stability, continuity and result credibility of phase noise measurement under the condition of short delay.

This invention provides a low-crosstalk signal demodulation device and method for fiber optic laser communication, belonging to the field of fiber optic communication technology. The device includes a fiber optic signal input port, an optical circulator, a polarization beam splitter / combiner module, a balanced photodetector unit, a low-noise amplification and quadrature demodulation module, an adaptive crosstalk cancellation unit, a MIMO equalization and decision unit, and a digital signal output port, connected in series according to the signal flow direction. It also includes a crosstalk monitoring and feedback unit bidirectionally connected to the low-noise amplification and quadrature demodulation module, the adaptive crosstalk cancellation unit, and the MIMO equalization and decision unit. This invention, employing the aforementioned low-crosstalk signal demodulation device and method for fiber optic laser communication, overcomes the limitations of traditional single-domain crosstalk suppression. Through the synergistic effect of optical path, circuit, and algorithm layers, it effectively suppresses crosstalk caused by multi-channel multiplexing, polarization mode dispersion, and backscattering, significantly improving demodulation accuracy, anti-interference capability, and system stability.

The application discloses a kind of dual-frequency modulation transfer spectroscopy laser frequency stabilization device and method, construct the dual-frequency modulation signal including first frequency component and second frequency component, according to dual-frequency modulation signal driving fiber electro-optic phase modulator to laser is carried out dual-frequency electro-optic phase modulation;Photoelectric detector carries out detection to the polarized beam splitter output light and obtains saturated absorption signal, to saturated absorption signal in turn carries out quadrature demodulation and low-pass filter processing and obtains first error signal and second error signal, first error signal and second error signal are superimposed to obtain dual-frequency error signal;Further, tunable laser is carried out closed-loop feedback control, realizes laser frequency stabilization.The application obtains two different frequency components error signal using dual-frequency modulation transfer spectroscopy detection technology, improves slope and intensity by adding operation, improves frequency discrimination sensitivity and anti-interference ability, is conducive to peak search determination and realizes the precision locking of laser frequency to rubidium absorption peak, with good practicability.

The present application relates to the technical field of precision phase measurement and digital signal processing, and particularly relates to a method and system for suppressing spectral aliasing and nonlinear distortion. The beat frequency signal is preprocessed and spectrum is constructed to obtain a normalized spectrum; peak value search is performed in a preset target frequency range to identify beat frequency, side frequency and pilot frequency signals to form an effective spectrum line set; nonlinear parasitic components are calculated to obtain folded parasitic spectrum lines, and the parasitic spectrum lines to be evaluated are obtained through constraint screening; branch processing is realized through suppression standard judgment, and selective narrowband notch suppression is performed on the parasitic spectrum lines meeting the conditions; digital heterodyne quadrature demodulation and low-pass filtering are performed on the signals before and after processing; and the suppression effect quantitative evaluation is completed according to the phase error and phase noise index, and the parameters are dynamically adjusted to realize the working condition adaptive optimization. The advantage lies in: accurately predicting and suppressing the composite interference, protecting the integrity of the effective signal, significantly improving the phase measurement accuracy and robustness, and widely applying to various scenes.

Method and system for automatic modulation classification (AMC) use time-series voltage signals representative of radio frequency (RF) signal envelope and frequency components as input features to a deep learning-based neural network, which enables classification of both modulation type and symbol rate without requiring in-phase and quadrature (IQ) demodulation. A feature extraction circuit captures RF signal envelope amplitude and frequency using stub-based sensing, and a Long Short-Term Memory (LSTM) neural network processes these features in a digitized form to classify the modulation and symbol rate with high accuracy and minimal latency.

The application provides an anti-interference acoustic signal data extraction method based on energy data sensing, and belongs to the technical field of underwater acoustic signal processing. The method comprises the following steps: A / D sampling and digital quadrature demodulation are performed on a received acoustic signal to obtain a baseband signal; low-pass filtering and down-sampling are performed on the baseband signal to obtain a pretreated signal; the pretreated signal is matched filtered by using a reference signal; a key improvement lies in that a local energy estimation function of the pretreated signal is calculated, and the matched filtering result is normalized with the energy estimation function to obtain a normalized detection signal. Through energy sensing normalization, the application effectively suppresses the shielding effect of strong interference signals on weak target signals due to non-quadrature reference signals and the "near-end strong and far-end weak" scene, significantly reduces the false recognition probability, and improves the accuracy and reliability of extracting a long-distance and low signal-to-noise ratio target beacon signal in a complex underwater acoustic environment. The application is suitable for underwater navigation, positioning and communication systems.

This application discloses a fully digital magnetic field measurement device and method, relating to the field of magnetic field measurement technology. The device generates a constant AC-DC superimposed current signal with adjustable frequency and amplitude, and outputs it to a Hall sensor placed in the magnetic field to be measured. It acquires the Hall voltage generated by the Hall sensor and performs analog-to-digital conversion to obtain a digital Hall signal. The digital Hall signal is quadrature demodulated to extract the in-phase and quadrature components. The magnetic field strength amplitude and phase are calculated based on the in-phase and quadrature components. The current is sampled in real time, and a closed-loop control signal is generated based on the deviation between a preset target current value and the actual sampled value to adjust the AC-DC superimposed current amplitude. Through a fully digital signal processing architecture and closed-loop control and output, high-precision, high-speed, and low-noise measurement of magnetic field strength and direction is achieved.

An amplitude demodulation implementation method applied to a secondary radar, the method comprising: performing frequency mixing on a reply signal to obtain an intermediate frequency signal; quantizing the intermediate frequency signal; performing quadrature demodulation on the quantized intermediate frequency signal to obtain a digital amplitude value, and using a piecewise linear calculation method to obtain a logarithmic digital amplitude. The logarithmic compression processing function of the secondary radar for a reply signal is implemented by an FPGA; after intermediate frequency digitization of the reply signal, a digital amplitude value is obtained via quadrature demodulation; and the digital amplitude value is processed in the FPGA by using a piecewise linear calculation method to approximate a logarithmic conversion characteristic, so as to obtain a logarithmic digital amplitude, which is very simple.

The invention discloses a high-precision capacitive displacement sensor based on double ADC switch proportional demodulation. According to the high-precision capacitance displacement sensor based on double-ADC switch proportional demodulation, the analog front-end circuit is used, a refined circuit model is established, modulation noise can be reduced, and the capacitance resolution of analog modulation can be improved; by using the double-ADC switch proportion measurement circuit, secondary alternate acquisition and reconstruction of modulation signals and carrier signals can be realized, so that gain fluctuation caused by carrier generation modules such as ADCs and DACs is inhibited; by using the digital quadrature demodulation circuit, the phase error introduced in the demodulation process can be reduced or eliminated; the bad influence of the DAC carrier gain and the ADC gain on the finally output baseband signal is small, the included phase error introduced in the demodulation process is small, and high-precision displacement detection can be achieved. The displacement sensor is widely applied to the technical field of displacement sensors.

The application discloses a nonlinear fitting method and system of an impedance equivalent model, voltage and current data are collected at configured frequency points through a frequency sweeping hardware system, corresponding impedance values are obtained through orthogonal demodulation for the data at each frequency, a matched impedance model is selected from a plurality of preset impedance equivalent circuits, a plurality of initial model parameters are predicted through a multi-physical field coupling initial value prediction algorithm, the initial model parameters are combined with a parameter physical constraint optimization strategy, and an optimal solution is obtained through nonlinear least square fitting, so that the algorithm has the advantages of accelerating the convergence speed and reducing the requirement for computing power, model parameters are automatically adjusted in the algorithm operation process, errors between model prediction values and actual measurement values are minimized, and the model parameters are continuously adjusted, so that accurate fitting of the equivalent model is realized.

The invention discloses a chaos incoherent underwater acoustic communication demodulation method, a chaos incoherent underwater acoustic communication demodulation system and a chaos incoherent underwater acoustic communication demodulation product based on channel weighting. The method comprises the following steps: 1, receiving a training sequence of an underwater acoustic chaos incoherent signal, and adaptively performing underwater acoustic channel estimation through an affine projection algorithm in combination with a copy signal to obtain a frequency domain channel response value; step 2, calculating energy of the underwater acoustic channel in a narrow band with a frequency modulation point to be demodulated as a center, and taking the energy as a demodulation weighted value; step 3, in an incoherent demodulation stage, calculating energy of each frequency point to be demodulated based on an orthogonal demodulation method, and then multiplying the energy by the demodulation weighted value calculated in the step 2 to obtain a demodulation energy value of each frequency point; and step 4, obtaining a final demodulation result of each frequency modulation point to be demodulated through hard decision. According to the invention, the chaotic incoherent signal is adopted, the influence of the underwater acoustic Doppler effect is less, and the confidentiality is better; and the influence of a channel on signal demodulation is fully considered, and compared with a traditional demodulation method, the method has better robustness.

This invention discloses a method and system for calculating the ultra-fine spectrum of a sampled signal, belonging to the field of weak signal detection technology. Calculating the spectrum of signals with extremely long sampling times presents problems such as large data volume and high computer memory requirements. This method divides the sampled data sequence of an ultra-low bandwidth modulated signal into segments of equal duration. Each segment is then subjected to quadrature demodulation, filtering, and decimation concatenation. The processed segments are then sequentially concatenated, and finally, a time-frequency transformation is performed to obtain the signal spectrum with ultra-fine frequency resolution. This calculation method significantly reduces the amount of data required for time-frequency transformation, allowing the processing of massive amounts of sampled data to be completed on a conventionally configured computer, yielding signal spectra with frequency resolution at the millihertz or even microhertz level. This allows for the observation and understanding of the extremely low-frequency spectral structure or near-end phase noise of the signal. This calculation method has strong versatility.

The invention discloses a surface acoustic wave double-frequency reader structure for multi-level soil temperature and humidity detection and a detection method. Aiming at the condition that the number of levels is large and the device adopts combination of time division multiple access and frequency division multiple access of two frequency bands of 840-845 MHz and 920-925 MHz, a direct digital frequency synthesizer of a transmitting link is mixed with a phase-locked loop to obtain double-frequency excitation signals which comprise two mirror image frequencies of 842.5 MHz and 922.5 MHz, a receiving link constructs a double-frequency channel through two duplexers, and the receiving link is connected with the receiving link through the two duplexers. Meanwhile, echo pulse string signals of all the double-frequency surface acoustic wave devices are received, and the signals are processed in parallel through a double-frequency digital quadrature demodulator to obtain soil temperature and humidity values of all levels. Compared with polling emission of excitation signals with two frequencies and time-sharing information processing, the method has the advantages that real-time performance is good, mirror image frequency does not need to be eliminated, the reader structure is remarkably simplified, and time sequence control is very simple.

The application designs a Coriolis mass flowmeter signal processing method based on orthogonal demodulation; an orthogonal demodulation method CH-QD based on correlation operation and Hilbert transform is proposed, first, autocorrelation operation is carried out on any one sensor signal, and the obtained autocorrelation signal is used as the same frequency cosine reference signal of the sensor signal; the autocorrelation signal is subjected to Hilbert transform, and the obtained Hilbert transform signal is used as the same frequency sine reference signal of the sensor signal; according to the same frequency and orthogonal relationship between the autocorrelation signal and the Hilbert transform signal thereof, the instantaneous frequency of the signal is calculated by complex number and trigonometric function operation; the two sensor signals are respectively subjected to sine and cosine reference signal demodulation, the center frequency of the signal is moved to the double frequency of the original frequency, and the low frequency component carrying the signal phase information is contained in the signal; the high frequency component is filtered out through a multi-stage low pass filter, and the low frequency component is retained; the low frequency component is used to extract the phase difference of the two signals, and the high-precision density, mass flow and other information of the fluid are provided.

The invention relates to the technical field of signal modulation, in particular to an analog orthogonal vector amplitude demodulation method and device. The method comprises the following steps of: firstly, performing orthogonal demodulation on a signal to be demodulated by combining an original reference signal VREF to obtain an in-phase signal VINX and an orthogonal signal VINY; and then amplitude demodulation is carried out on the in-phase signal VINX and the orthogonal signal VINY to obtain a final demodulation result VOUT. According to the invention, a first multiplication divider, a second multiplication divider and an addition unit are constructed for amplitude demodulation. According to the analog orthogonal vector amplitude demodulation method provided by the invention, two multiplication dividers and an addition unit are constructed, so that an implicit operation logic combining squaring, addition and feedback is realized, the dynamic range of a demodulation circuit is effectively expanded, and the demodulation efficiency is improved. The core problem that the analog demodulation dynamic range of a traditional explicit operation (direct extraction) structure is insufficient is solved.

The application discloses a kind of monitoring method and system of electric power grounding system, applied to resistance detection technical field, method includes: obtaining the position distribution information of each ground body in target electric power grounding system;Based on position distribution information, the mutual impedance information of each ground body is obtained;Determine the target excitation frequency point of ground body;The target excitation signal is applied to corresponding ground body, and corresponding response signal is obtained;Orthogonal demodulation is carried out to the target impedance component extracted from response signal, and resistance response component and reactance response component are obtained;According to resistance response component, the equivalent resistance value of ground body is obtained, and the impedance data of ground body is determined based on reactance response component to process equivalent resistance value;Based on the impedance data of ground body, the resistance monitoring data of target electric power grounding system is obtained.The monitoring method and system of electric power grounding system provided by the application effectively improve the accuracy of resistance monitoring of the electric power grounding system of multiple ground body.

The invention discloses a light-induced thermoelastic multi-component gas detection device and method based on quadrature modulation, which adopts a technical path combining double-path quadrature phase modulation and single-path quadrature demodulation, that is, two tunable lasers are respectively driven by sinusoidal signals with the same modulation frequency but orthogonal phases; the two laser beams are combined by the wavelength division multiplexer, collimated by the collimator, acted by the gas chamber and the gas and focused by the lens and then radiated to the surface of the quartz tuning fork, a piezoelectric signal generated by the quartz tuning fork comprises excitation mixing information of the two gases, and the signal is amplified by the preamplifier and then sent to the lock-in amplifier; and the phase-locked amplifier synchronously calculates two components X and Y which are orthogonal to each other according to a reference signal with the same frequency as the laser modulation signal, and the two components respectively and independently correspond to the concentration information of the two target gases, so that real-time, synchronous and crosstalk-free measurement of the two-component gases is realized.

The present application relates to the technical field of vibration monitoring, and discloses a kind of for historical building microvibration monitoring optical fiber sensing data analysis method and system, the method includes: the original interference signal is quadrature demodulated, and vibration in-phase component and quadrature component are obtained, and vibration complex signal is constructed with this as real part and imaginary part.The signal is unwound to obtain continuous vibration phase sequence, and vibration change sequence is obtained after high-pass filtering.The characteristic quantity of each band component in the synthesis sequence is formed to form the original characteristic vector.Based on the sensitivity of historical building monitoring site to vibration, the characteristic vector is fused to obtain the comprehensive vibration index.According to the concentration trend and dispersion degree of the index, determine the dynamic reference value and fluctuation range, judge the vibration deviation degree against the fluctuation range, and obtain the information evaluation conclusion;The present application can improve the accuracy of optical fiber sensing data analysis for historical building microvibration monitoring.

The application discloses a bearing fault acoustic detection method and system based on fractional harmonic phase-locked amplification, acoustics signals of a target motor are acquired, the shaft rotation frequency of the motor shaft is measured in real time, and is synchronized to a fractional phase-locked loop; according to the geometric parameters of the bearing, the bearing fault characteristic frequency is calculated, the bearing fault characteristic frequency is a non-integer multiple of the shaft rotation frequency, a reference signal synchronized to the bearing fault characteristic frequency is generated through the fractional phase-locked loop, and the acquired acoustics signals and the generated reference signal are detected in a phase-sensitive manner through a phase-locked amplifier; specifically, the acoustics signals and the reference signal are quadrature demodulated to generate in-phase components and quadrature components, direct current components are extracted through low-pass filtering, and then the vibration amplitude and phase information corresponding to the bearing fault characteristic frequency are calculated; according to the comparison between the vibration amplitude and a preset baseline, harmonic consistency and phase stability, the bearing fault type and severity are determined.

The application provides a differential quadrature demodulation method for dynamic direct current offset, and belongs to the technical field of signal processing.The method comprises the following steps: collecting a quadrature baseband signal containing target motion information, and sequentially performing differential operation and differential cross multiplication operation to obtain a preliminary demodulation phase; using the preliminary demodulation phase and the differential quadrature baseband signal to obtain a reconstructed quadrature baseband signal; calculating the variance of the differential demodulation phase according to the length of a preset window, obtaining a judgment threshold, detecting an abnormal region set of the differential demodulation phase, excluding all abnormal regions of the reconstructed quadrature baseband signal, and performing differential cross multiplication operation to obtain a fine calibration demodulation phase; and fitting and repairing all abnormal regions in the fine calibration demodulation phase to obtain a target motion trajectory subjected to differential quadrature demodulation.The application can effectively improve the robustness, real-time performance and accuracy of demodulation of motion information.

The invention relates to the technical field of communication, discloses a millimeter wave beam forming chip phase noise suppression method and system, and aims to solve the problems of high cost, high power consumption, remarkable processing delay and poor environmental adaptability of a phase noise suppression scheme in the prior art. The method comprises the following steps: coupling an output signal of a local oscillator in real time and digitizing to obtain a monitoring signal containing phase noise; an instantaneous phase error sequence is extracted through digital orthogonal demodulation and a CORDIC algorithm; and performing dynamic prediction on the phase noise by using the LMS or RLS adaptive prediction model. Through a feed-forward digital compensation mechanism, real-time prediction and offset of phase noise are realized in a baseband domain, the beam forming precision and the system robustness are improved, low-cost oscillator application is supported, the overall power consumption and cost are reduced, and meanwhile, the stability and the anti-interference capability of a communication link are improved.

A demodulator (100) comprising: a demodulation element (10) which outputs a demodulated signal which is demodulated from a modulated signal; an integration element (60a) which integrates the demodulated signal; a zone detection element (60b) which detects a replacement target zone in the demodulated signal based on an integrated signal output by the integration element (60a); and a replacement element (60c) which replaces a signal of the replacement target zone in the demodulated signal with a replacement target signal; wherein the demodulation element (10) comprises: an orthogonal demodulator (20) which demodulates from the modulated signal, which is FM modulated, an I signal and a Q signal which are orthogonal to each other; an A / D conversion element (30) which converts the I signal and the Q signal, which are in an analog form and are received by the orthogonal demodulator (20), into digital signals;a filter element (40) which cuts out a high-frequency band higher than a predetermined cut-off frequency from the I signal and the Q signal, which have been converted into digital signals by the A / D conversion element (30); and an FM demodulator (50) which outputs the demodulated signal obtained by correcting a differential value of the arctangent of the I signal and the Q signal to lie within a predetermined numerical range, wherein the differential value is obtained by differentiating the arctangent of the I signal and the Q signal received by the filter element (40).

This invention belongs to the field of power equipment condition monitoring and fluid non-destructive testing technology, specifically relating to a method and system for ultrasonic detection and dynamic visualization of moving air bubbles in the insulating oil of oil-filled electrical equipment such as ultra-high voltage transformers, using multi-angle dynamic focusing for bubble velocity measurement and positioning. It is applied to bubble detection in the complex oil duct environment of ultra-high voltage transformers. The method performs orthogonal demodulation and filtering on the received signal to extract the low-frequency Doppler component. Then, digital beamforming technology is used to achieve multi-angle dynamic focusing of the bubble echo, and the data is converted from a fast time dimension to a slow time dimension. The Doppler frequency shift is extracted by analyzing the time-frequency characteristics of the signal using short-time Fourier transform. The bubble velocity vector is estimated based on least squares fitting, thereby simultaneously achieving velocity detection and spatial positioning. This invention, with limited data, calculates the vector velocity of the bubble movement based on spatial information from multiple dynamically focused angles and achieves positioning.

The invention provides a monitoring device and method for a magnetic ring in a server, and can be applied to the technical field of electromagnetic compatibility. According to the device, a first detection module detects the surface temperature of a magnet of a magnetic ring and current flowing through a wire of the magnetic ring; the second detection module transmits an excitation signal to the magnetic ring, detects a reflection signal generated by the magnetic ring under the action of the excitation signal, and performs orthogonal demodulation on the reflection signal to obtain an in-phase component and an orthogonal component of the baseband signal; the processor determines the total thermal load and the electric impact energy of the magnetic ring according to the surface temperature and the current, and calculates the first impedance change rate of the magnetic ring based on the total thermal load and the electric impact energy; the maintenance module is controlled to maintain the magnetic ring; calculating a second impedance change rate of the magnetic ring according to the in-phase component and the orthogonal component; the coefficients used for the total thermal load and the electrical impact energy when the first impedance change rate is calculated are updated as a function of the difference between the second impedance change rate and the current first impedance change rate.

The invention relates to the technical field of wireless communication, and discloses an environment backscatter communication enhancement method and system based on biphase detection, and the method comprises the steps: obtaining an environment radio frequency signal received by an antenna, and generating an in-phase component I-path signal and an orthogonal component Q-path signal through two-path orthogonal demodulation, generating a binary state identifier representing an antenna matching state; a historical state identifier sequence is formed based on the identifier, an energy-communication alternating period is identified, the average duration is counted, and a phase switching prediction signal is generated in combination with the identifier; receiving a prediction signal to generate a switching control sequence, analyzing a target state type to generate a modulation control instruction, and executing the modulation control instruction to form closed-loop optimization; according to the invention, bit synchronization drift and judgment threshold offset caused by carrier multipath attenuation in the shadow area of the large-span metal structure can be effectively relieved, and the communication stability is guaranteed.

The application belongs to the field of space-based microwave radar, and discloses a space-based detection radar channel consistency calibration method based on an active calibrator. The active calibrator is arranged on the ground to actively emit a point frequency continuous wave signal, and the space-based detection radar beam direction is adjusted to make the beam dwell and continuously scan the active calibrator, so that a high signal-to-noise ratio, stable and controllable external radiation echo signal is obtained. The received point frequency continuous wave signal is multiplied by a carrier frequency signal and then subjected to quadrature demodulation to obtain demodulation signals of each channel; distance direction FFT is performed on the demodulation signals to obtain peak amplitude and peak phase; the phase difference and amplitude difference of each channel relative to a reference channel are calculated to generate a channel consistency calibration parameter file for radar calling. The precision and stability of the space-based detection radar channel consistency calibration are improved, the method is suitable for a multi-frequency band and multi-channel system, and has operability and popularization value in engineering application.

The application discloses a kind of based on flat double-winding coil electric vehicle wireless charging foreign matter detection system, including flat double-winding detection coil group, high-frequency excitation signal source, resonance amplification circuit, high-pass filter, quadrature demodulator, ADC module, detection coil control switch and processor;Processor controls detection coil control switch based on time division multiplexing control method, changes the way that flat double-winding detection coil group is connected to resonance amplification circuit, realizes the switching between metal foreign matter and biological foreign matter detection mode;Resonance amplification circuit input end is connected to high-frequency excitation signal source, and output end is sequentially processed by high-pass filter and quadrature demodulator, and voltage amplitude and phase information sampling are realized by ADC module after it, and processor realizes the distinguishing detection of metal foreign matter and biological foreign matter according to the change of voltage amplitude and phase, and its effect is: foreign matter detection system and wireless charging system can work independently, and the effective detection of metal foreign matter and biological foreign matter can be realized.