589 results about "Frequency mixing" patented technology

The invention discloses a frequency source synthesis system and method based on a frequency agility radar, and belongs to the technical field of microwave radio frequency, and the method specifically comprises the steps: generating a target clock signal, carrying out the frequency processing of the target clock signal to generate a frequency multiplication signal, and dividing the frequency multiplication signal into two clock signals through a power divider; performing frequency multiplication processing on one path of clock signal, taking the processed signal as a clock reference signal of a direct digital synthesizer, generating an analog signal according to the clock reference signal, and calibrating the analog signal as an output signal; performing frequency multiplication processing on the other path of clock signal, and taking the processed clock signal as a local oscillation signal of the frequency mixer; performing frequency conversion processing to obtain a frequency mixing signal, performing quadruplicated frequency processing on the frequency mixing signal, and calibrating the processed frequency mixing signal as a final output signal; according to the invention, the frequency source has the characteristics of low phase noise, rapid agility, fine resolution and miniaturization at the same time.

The invention discloses a frequency spectrum refining frequency point tracking type optical frequency domain reflection distributed sensing method, which comprises the following steps of: inputting probe light into a sensing optical fiber engraved with weak reflection points to obtain backscattered light; carrying out coherent frequency mixing on the backscattered light and the reference light, and then carrying out photoelectric conversion to obtain an electric signal containing weak reflection point information; aD sampling is carried out on the electric signal containing the weak reflection point information, and a first discrete signal sequence is obtained; performing frequency spectrum refinement on the first discrete signal sequence to obtain a refined beat frequency spectrum; performing peak searching operation on the refined beat frequency spectrum to obtain weak reflection beat frequency points at different positions in different measurement periods; extracting phase values of beat frequency points of weak reflection points at different positions in different measurement periods by utilizing Hilbert transform; and carrying out phase demodulation on the phase values of the beat frequency points of the weak reflection points at different positions in different measurement periods to obtain the change condition of parameters measured by the sensing optical fiber. Errors caused by the Doppler effect can be eliminated.

The invention belongs to the field of unmanned aerial vehicle technologies and radars, and discloses a radar phase difference unmanned aerial vehicle height measurement method based on frequency spectrum refinement calibration, which comprises the following steps: receiving a radar echo carrier frequency signal, and forming a radar data cube by an intermediate frequency signal after frequency mixing processing; performing time-frequency domain conversion on the data cube distance dimension to obtain a radar one-dimensional distance image sequence; interference clutters are filtered based on a constant false alarm detection technology, and a maximum peak value in a range is searched to determine a distance threshold of an observation area; performing frequency spectrum refinement processing on a specific frequency band of the observation area by using Chirp-Z transformation, constructing a quadratic polynomial in combination with parabola fitting to perform spectral line calibration, and obtaining frequency information of the observation area after frequency spectrum refinement calibration; and extracting a phase sequence of an observation area distance threshold, unwrapping adjacent frame phases by using phase unwrapping, and determining height information of the unmanned aerial vehicle relative to the ground by combining frequency and phase information. The unmanned aerial vehicle can be assisted to quickly feed back the relative ground height, and the collision risk is avoided.

The invention relates to the technical field of spectrum detection, and particularly provides a passive laser heterodyne double-balance spectrum detection method and device, and the method comprises the steps: carrying out the frequency mixing and differential processing of an input narrow-linewidth laser local oscillator signal and a wide-spectrum incoherent target optical signal through employing an optical mixer and a photodiode, and obtaining a laser heterodyne double-balance spectrum. Two paths of random time beat frequency photocurrent signals with the phase difference of 90 degrees are generated, the random time beat frequency photocurrent signals comprise information such as the spectrum of signal light, and the spectrum information of the signal light can be recovered by processing the output photocurrent signals through methods such as filtering and integration. The narrow linewidth and wavelength tunable characteristics of the narrow linewidth laser local oscillation signal can be utilized to perform high spectral resolution information acquisition on the wide spectrum incoherent optical signal, the utilization efficiency of the local oscillation light is effectively improved, common mode noise and part of system noise are eliminated, and the signal-to-noise ratio of the output signal is enhanced.

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 differential signal synthesis circuit of a double-IQ mixer, which belongs to the technical field of radio frequency microwave testing and comprises two single-ended IQ mixing modules, a 180-degree phase shift module and an in-phase combination module or a power division module. The single-ended IQ frequency mixing module is used for up-converting the single-ended IQ baseband signal to radio frequency or down-converting the radio frequency signal to the single-ended IQ baseband signal; the 180-degree phase shift module is used for converting an input signal into two paths of signals with a phase difference of 180 degrees; and the power division module is used for converting the radio frequency input signal into two paths of signals with the phase difference of 0 degree. According to the invention, the IQ mixer with a differential structure is constructed, so that the microwave band of the IQ mixer is comprehensively improved in the index aspects of local oscillator leakage, even-order component suppression, common-mode interference suppression, signal-to-noise ratio and the like; according to the invention, single-ended IQ mixers with various types and complete frequency bands can be constructed into a differential structure form, and signal indexes in numerous application scenes are improved.

The invention discloses an image denoising method and system based on an adversarial frequency mixing technology, and belongs to the field of image processing. The method comprises the steps of obtaining a training data set of a noise-containing image and a noise-free image, inputting the noise image into a denoising network, predicting an initial denoised image, converting the noise image and the initial denoised image into a frequency domain by using Fourier transform, extracting a low-frequency band, a middle-frequency band and a high-frequency band in a layered manner, generating a mixed mask of each frequency band, and outputting the mixed mask of each frequency band. A mixed frequency band is obtained and recombined, a mixed noise image is obtained through inverse Fourier transform, the mixed noise image is input into a denoising network, and a final denoising image is obtained; determining a first loss function based on the initial de-noised image, the final de-noised image and the noiseless image, and training and optimizing a de-noising network; and inputting a to-be-denoised image into the optimized denoising network, and outputting a target image. The method can effectively solve the problem that the existing denoising network is insufficient in generalization ability when facing unknown noise distribution.

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.

The invention belongs to the technical field of flow velocity measurement, and relates to a 4D millimeter wave radar flow velocity measurement method and system. The method comprises the following steps: emitting frequency-modulated continuous waves to irradiate the water surface by using a 4D millimeter-wave radar; receiving a water surface emission signal and carrying out frequency mixing to obtain a difference frequency signal; performing two-dimensional FFT processing on the difference frequency signal to obtain distance information from the emission point to a river reflection point, mirror image speed information of the reflection point relative to the radar and angle information of the reflection point relative to the emission point; establishing a coordinate system; converting the distance information and the angle information into coordinate data; determining an included angle between the river surface and a transmitted wave of a radar normal corresponding to the reflection point; and determining the flow velocities of a plurality of reflection points on the same straight line of the river surface, and averaging to obtain the river surface flow velocity. According to the invention, through the 4D millimeter wave radar, three-dimensional construction is carried out on the river plane, errors caused by installation errors or equipment aging are avoided, and the effect of accurate measurement is achieved; through information of four dimensions, complete four-dimensional space information is constructed.

The invention discloses a wavelength demodulation system for wavelength division multiplexing based on a microring resonator, comprising a microring resonator chip, a modulation signal generating circuit, a photoelectric signal conversion circuit and a frequency mixing filter circuit; the modulation signal generating circuit generates a sinusoidal oscillation modulation signal with a DC bias, and transmits it to the microring resonator chip and the frequency mixing filter circuit; the microring resonator chip converts input optical signals of different wavelengths into optical signals related to the wavelength, and transmits them to the photoelectric signal conversion circuit; the photoelectric signal conversion circuit converts the optical signal output by the microring resonator chip into an electrical signal, and transmits it to the frequency mixing filter circuit after amplification, and the frequency mixing filter circuit realizes the mixing and filtering of the sinusoidal oscillation modulation signal transmitted by the modulation signal generating circuit and the converted electrical signal, and outputs the demodulated voltage signal. The demodulation system disclosed by the invention can demodulate the sensor reflection signal based on a wide-spectrum light source, has low cost and small size, and can realize large-scale multiplexing.

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.

The present application discloses a multi-channel transceiving device, a calibration apparatus, system, and method, and an electronic device. The multi-channel transceiving device comprises a plurality of service transceiving channels and a plurality of antenna units correspondingly connected to the service transceiving channels. The multi-channel transceiving device comprises a device intermediate frequency port. The device intermediate frequency port is connected to an external frequency mixing radiation link, so that an intermediate frequency circuit in a reference transceiving channel carries out, by means of the external frequency mixing radiation link, radio frequency signal transceiving with the antenna unit corresponding to a service transceiving channel to be calibrated. The gain of the service transceiving channel to be calibrated is determined by determining the power of a transmitted signal, the power of a received signal, the path loss of the external frequency mixing radiation link, and the calibrated gain of the intermediate frequency circuit in the reference transceiving channel, and calibration is performed. In the present application, the calibration stage does not require long-term occupation of large-bandwidth and high-frequency test instruments. The external frequency mixing radiation link can use local oscillator signals inside the multi-channel transceiving device, and frequency synchronization can be achieved without complex synchronization schemes.

The invention provides an orthogonal down-conversion mixer, which comprises a first signal input port, a signal processing module and a mixing module, and is characterized in that a radio frequency signal is converted into a differential radio frequency signal through the first signal input port, and phase shift, amplification and impedance matching are performed on an initial local oscillator signal through the signal processing module; a first local oscillator signal and a second local oscillator signal are used for receiving a differential radio frequency signal, two local oscillator signals with orthogonal phases are obtained, the differential radio frequency signal is amplified through a pseudo-differential structure in a frequency mixing module, and frequency mixing is performed on the first local oscillator signal, the second local oscillator signal and the amplified differential radio frequency signal to obtain two target intermediate frequency signals. According to the orthogonal down-conversion mixer provided by the invention, the differential radio frequency signal is amplified through the pseudo-differential structure, the noise coefficient and power consumption of the mixer are reduced, the mixing speed is increased through the two local oscillator signals, and the noise coefficient of the mixer is further reduced.

The invention discloses an underwater echo ranging method based on mobile phone sound signals. The method comprises the following steps: discontinuously transmitting customized signals by using a mobile phone loudspeaker, receiving return signals by using a mobile phone microphone, and dividing a plurality of key frame signals in the return signals; performing filtering, frequency mixing, separation, denoising and difference processing on each key frame signal and a customized signal in sequence to obtain a frequency difference; performing filtering, fast Fourier transform and difference processing on each key frame signal in sequence to obtain frequency deviation; adding the frequency difference and the frequency offset of each key frame signal to obtain a frequency comprehensive offset value of the key frame signal, further performing multi-frame joint judgment to filter out abnormal values, and averaging residual values to obtain a frequency comprehensive offset mean value; and the distance between the mobile phone and the water bottom is obtained through calculation processing by combining customized signals. According to the invention, high-precision acoustic signal echo distance measurement can be realized in an underwater environment with low cost, and the method can be applied to the fields of drowning detection, swimming rescue and the like.

The invention discloses a multi-channel leaky coaxial cable fault positioning system and method, and belongs to the technical field of rail transit leaky coaxial cable fault positioning and monitoring. The system comprises a modulation signal generator, a circulator, an SPTD module, an FPGA signal processor and an upper computer. The system only needs to install a monitoring device at one end of the leaky coaxial cable, and is convenient to implement. The ZYNQ control panel is used for controlling IO signals, so that the SPTD switch is controlled to realize switching of monitoring channels, and multi-channel fault detection and positioning are realized; the unattended operation is realized, the detection and positioning cost is effectively reduced, and the detection efficiency is improved. According to the method, by introducing the phase error compensation function of the transmitting signal and the phase error compensation function of the echo signal, the phase compensation of the frequency mixing signal is realized, so that the phase error of the fault detection signal is reduced, the detection precision is improved, and the accuracy of fault judgment, fault point positioning and fault type judgment is effectively improved.

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 a transmission-type nondestructive testing method and system based on a terahertz area array detector, and belongs to the technical field of terahertz imaging nondestructive testing. According to the frequency mixing array imaging system based on the terahertz technology and based on shaping and focusing of terahertz wave beams, a ceramic or glass fiber reinforced composite material sample piece for aerospace is placed between the shaping lens and the imaging lens, transmission type detection is carried out on the sample piece, and the frequency mixing array detector obtains surface area information of the sample piece; and typical defect feature processing and defect identification are carried out, so that the state of the sample piece is rapidly evaluated. The invention aims to solve the problems of low efficiency and low imaging quality in the existing terahertz nondestructive testing technology. By adopting the terahertz area array detector and the optical imaging assembly, rapid and high-resolution nondestructive detection can be realized, and the terahertz area array detector is particularly suitable for application scenes requiring high detection efficiency and imaging quality.

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 provides an optical frequency comb frequency stabilizing device and method, and the device comprises a first optical filter which is configured to carry out the filtering of an optical frequency comb, and obtains two comb teeth to be locked; the oscillation loop is configured to perform oscillation based on the two comb teeth to be locked and generate an oscillation radio frequency signal of a first angular frequency and an oscillation radio frequency signal of a second angular frequency; and the feedback controller is configured to perform frequency mixing processing on the oscillation radio frequency signal of the first angular frequency, the oscillation radio frequency signal of the second angular frequency and the radio frequency reference signal to extract an error signal changing along with time, and output a control signal based on the error signal to perform frequency locking on the optical frequency comb.

The invention relates to a calculation method and device for an intermediate frequency domain amplitude phase angle in a memristor array, and the method comprises the steps: obtaining a time domain input signal corresponding to a target memristor array, and calculating a cosine frequency mixing signal and a sine frequency mixing signal based on the time domain input signal, a preset cosine signal and a preset sine signal; respectively applying the cosine frequency mixing signal and the sine frequency mixing signal to corresponding row lines of the target memristor array so as to calculate cosine current data and sine current data based on discrete Fourier transform matrixes of the corresponding row lines; and obtaining current information of each frequency point in the target memristor array based on the cosine current data and the sine current data, and reading phase information and amplitude information corresponding to each frequency point in the current information through a preset phase discriminator and a peak detector. Therefore, the problems that in the prior art, the amplitude and the phase cannot be directly calculated under the condition that extra hardware overhead and operation delay are not increased, and the frequency domain amplitude phase angle calculation efficiency is greatly affected are solved.

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 belongs to the field of electronic circuits, and provides an excitation control system based on a passive and wireless ultrasonic transducer, which is characterized in that a first transmitting circuit receives a high-frequency excitation signal and generates a high-frequency electromagnetic wave signal after power amplification; the pulse excitation circuit based on the PNP triode rectifies the received high-frequency electromagnetic wave signal and stores energy, and generates an instantaneous pulse excitation signal; the second transmitting circuit receives the high-frequency carrier signal, provides the high-frequency carrier signal to a passive wireless ultrasonic transducer end after power amplification, and sends a demodulation reference signal to the receiving circuit; the passive wireless ultrasonic transducer end excites a low-frequency ultrasonic signal of which the frequency is the same as the resonant frequency, and after the high-frequency carrier signal is received, the low-frequency ultrasonic signal and the high-frequency carrier signal are subjected to frequency mixing modulation to obtain a high-frequency modulation signal; and the receiving circuit filters and amplifies the high-frequency modulation signal and then performs frequency mixing demodulation on the high-frequency modulation signal and a demodulation reference signal to obtain a low-frequency ultrasonic sensing signal. The power of the ultrasonic transducer can be 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.