247 results about "Frequency mixing" patented technology

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.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The utility model provides a phase-locked loop circuit, which relates to the technical field of phase-locked loops and comprises a reference frequency multiplication filtering unit, an auxiliary mixing frequency-locked phase loop unit and a main mixing frequency-locked phase loop unit. The reference frequency multiplication filtering unit is used for receiving the first reference signal, performing frequency division processing on the first reference signal, performing frequency multiplication filtering on one path of signal after frequency division processing, and outputting a low-phase noise signal; the auxiliary frequency-mixing phase-locked loop unit is used for receiving the low-phase noise signal output by the reference frequency-doubling filtering unit and the other path of signal obtained by frequency division of the reference frequency-doubling filtering unit, and outputting an LO reference signal after frequency mixing and phase discrimination; and the main frequency mixing phase-locked loop unit is used for receiving the second reference signal and the LO reference signal output by the auxiliary frequency mixing phase-locked loop unit, and outputting a coherent signal after frequency mixing and phase discrimination. According to the utility model, the LMX2820 is used as the phase discriminator, the phase detection range is small, the locking detection can be easier, and the practicability is strong.

The invention belongs to the technical field of measurement and testing, and relates to a multichannel ultra-low noise phase synchronization frequency selectable clock synthesis device. The device comprises an ultra-low phase noise frequency multiplication unit, an analog discrete phase-locked loop unit, a frequency mixing filtering unit and a multi-path synchronous power division unit which are connected in sequence. An analog microwave device is selected, so that the phase noise influence of a digital device on a clock signal is avoided; and meanwhile, a plurality of analog discrete phase-locked loops are adopted to realize an ultra-low phase noise clock signal, frequency mixing and filtering are performed to obtain a clock signal with the required frequency, and the phase is synchronized with an external reference clock. Functional unitization is carried out, the design logic is clear, and combination design is facilitated.

The invention discloses a small-sized wide instantaneous bandwidth radio frequency receiving front-end SiP module based on an HTCC, and belongs to the technical field of microwaves and radio frequency. The radio frequency receiving front end is realized on the basis of an SiP module of the HTCC, the mirror image frequency is far away from the radio frequency signal frequency spectrum through a high local oscillator dual-frequency conversion mode, and the spurious component generated by frequency mixing is moved to a high-frequency area outside an intermediate-frequency passband, so that wide instantaneous bandwidth and high spurious suppression are realized. According to the invention, miniaturization of the SiP module is realized based on the HTCC technology; a secondary frequency conversion superheterodyne circuit architecture and a high local oscillator design are combined, so that the instantaneous working bandwidth is widened to 4GHz, and meanwhile, high spurious suppression is realized; in addition, the vertical interconnection structure is improved, long-distance low-loss transmission of radio-frequency signals is achieved, and the size is further reduced. The ultra-wideband low-noise amplifier has the advantages of miniaturization, wide instantaneous bandwidth, low noise amplification and high spurious suppression, and a solution is provided for miniaturization and low-cost mass production of an ultra-wideband radio frequency system.

The invention provides a space laser communication fine tracking assembly, which adopts a two-stage closed-loop control system to realize high-precision tracking, the first stage adopts a light spot centroid tracking technology and adjusts a light beam direction in real time through elements such as an FSM fast reflector and a CMOS camera to compensate miss distance, and the second stage adopts an optical fiber nutation coherent tracking technology to compensate miss distance. According to the system, the micro-electromechanical system (MEMS) mirror, the nutation device, photoelectric detection and the like are combined, the tracking precision is further improved through optical fiber coupling and frequency mixing processing, the FPGA programmable processor serves as a core to process images and signals and generate control signals to drive the reflector and the nutation device, accurate alignment of receiving and transmitting optical axes is ensured, and efficient and stable space laser communication is achieved. According to the invention, through combination of the first-stage light spot positioning tracking technology and the second-stage space nutation coherent tracking technology, precise control and tracking of the light spot position in space laser communication are realized, and the suppression bandwidth and precision of precise tracking are effectively improved.

The utility model discloses a multi-frequency metal detector which comprises a single-chip microcomputer master controller, a key module, a receiving module, a transmitting module, an FM module, a single-chip microcomputer programming module, an adjustable power supply module, a frequency mixing control module, a power supply module, a sound amplification module and a storage module. Wherein the transmitting module is provided with an H-bridge structure, and the H-bridge structure is connected in series with an LC to generate sine wave current potential eddy current to perform same-frequency resonance on various metals; the key module, the receiving module, the transmitting module, the FM module, the single-chip microcomputer programming module, the adjustable power supply module and the frequency mixing control module are electrically connected with the single-chip microcomputer master controller. The power supply module, the sound amplification module and the storage module are electrically connected with the frequency mixing control module. The multi-frequency metal detector provided by the utility model is stable in operation, high in efficiency, capable of generating 144 frequencies, strong in signal and high in metal detection efficiency.

The invention discloses a multi-channel photoelectric delay line radar extended target simulation system and method, belonging to the field of radar simulation technology. The system comprises a radar signal receiving and echo signal transmitting module, a frequency mixing and echo Doppler frequency shift module, a multi-target echo simulation module, a delay module and an attenuation module. The method comprises the following steps: mixing a received radar signal to convert it into an intermediate frequency signal; performing multi-target echo simulation on the intermediate frequency signal to convert it into a multi-channel intermediate frequency signal; delaying and attenuating each branch signal of the multi-channel intermediate frequency signal to obtain a delayed and attenuated multi-channel intermediate frequency signal; combining the delayed and attenuated multi-channel intermediate frequency signal to generate an intermediate frequency signal carrying multi-target information; mixing and transmitting the intermediate frequency signal to load Doppler frequency shift information to obtain a simulated target echo signal, thereby completing the simulation of the target echo.

The invention discloses a device and a method for testing frequency domain characteristics of a high-speed optoelectronic device. The device comprises a laser, a sawtooth wave generator, a signal source, an acousto-optic modulator, an electro-optic intensity modulator, a low-frequency photoelectric detector, a frequency spectrograph and a computer. An electro-optic intensity modulator is driven through a sawtooth wave modulation technology, and frequency-shifted and non-frequency-shifted optical carriers and frequency-shifted and non-frequency-shifted radio frequency optical sidebands are synchronously generated in an optical path in combination with radio frequency signal modulation. And after the signal is subjected to beat frequency processing by the photoelectric detector, the power of the frequency shift signal in different working states is measured by the frequency spectrograph, so that the frequency domain characteristic parameters of the photoelectric device to be measured are obtained. The method is based on sawtooth wave modulation and an amplitude comparison method, frequency domain response characteristics of a single / dual-drive electro-optic intensity modulator, dual-parallel electro-optic intensity modulation and a photoelectric detector can be accurately represented, the test method is simple, and dependence on a high-frequency test instrument is effectively reduced.

The invention discloses a parallel port type hexagonal frequency mixing solid-state transformer and a regulation and control method and device thereof, and the method comprises the steps: under the conditions that the direct-current active power and the alternating-current active power of the solid-state transformer are equal, and the instantaneous active power absorbed by each sub-bridge arm is 0, calculating the frequency of each sub-bridge arm in each sub-bridge arm; the stability relation between the fundamental frequency alternating current port current distribution coefficient and the intermediate frequency alternating current port current distribution coefficient is determined; and calculating a bridge arm circulation current through the stability relationship, thereby calculating to obtain a bridge arm circulation voltage reference value, calculating to obtain a sub-module capacitor voltage reference value of each sub-bridge arm, superposing each sub-module capacitor voltage correction component of each sub-bridge arm, obtaining a corresponding optimized sub-module capacitor voltage, and generating a corresponding modulation signal. By the adoption of the technical scheme, the multi-scene access requirement of the alternating current and direct current hybrid power distribution network is met, and inherent decoupling of three-frequency components including direct current, fundamental frequency and intermediate frequency can be achieved without an additional frequency selection network under the corresponding control method.

This invention discloses a method for quantifying the wear depth of finger sleeves used in nuclear power plant neutron flux measurement. The method includes the following steps: a. Measuring the actual dimensions of the finger sleeves in a nuclear power plant, establishing simulation models and performing simulation calculations for finger sleeves with annular and wedge-shaped defects; b. Establishing a unified calibration process, calibrating the simulation signals, and using the model to calculate signals at multiple frequencies for different finger sleeve defects; c. Performing frequency mixing calculations on the multi-frequency simulation signals to eliminate signals from the external sleeve structure; d. Drawing a graph showing the relationship between defect depth and circumferential angle and the amplitude and phase of the simulation signal, based on the specific parameters of the defect; e. Importing the measured signal values ​​into the drawn image, and quantizing the signal to defect parameters based on coordinates and legend information. This patent effectively reduces the quantization error of finger sleeve wear depth in Bobbin probe eddy current signals, improves the reliability of quantization, and can also quantify the wear angle of unilateral wedge-shaped wear.

The application discloses a six-tone signal generation circuit system, and relates to the technical field of circuit design, comprising: a quadrature frequency mixing module, a local oscillator driving module, a frequency mixing module, a signal synthesis module and a power amplification module; the quadrature frequency mixing module is used for frequency conversion of input first and second differential quadrature signals to first and sixth output signal frequencies; the signal output by the quadrature frequency mixing module, containing the first and sixth output signal frequencies, is used as the input of the signal synthesis module and the local oscillator signal of the frequency mixing module; the local oscillator driving module is used for amplifying the signal containing the first and sixth output signal frequencies as the local oscillator of the frequency mixing module; the frequency mixing module is used for frequency conversion of input differential signals to second, third, fourth and fifth output signal frequencies; the signal synthesis module is used for synthesizing the above six-tone signals; and the power amplification module is used for wideband amplification of the output six-tone signals and improvement of output power. The circuit system effectively solves the technical problem of multi-tone signal generation in a quantum conditioning circuit.

The invention provides an aircraft ground angle measuring system and method. The system comprises a data processing unit, a transmit-receive unit and an antenna unit which are installed on an aircraft and connected in sequence. The transceiving unit comprises a transmitter and a receiver; the antenna unit comprises a transmitting antenna connected with the transmitter, and a first receiving antenna and a second receiving antenna which are connected with the receiver; the transmitting antenna radiates a transmitting signal outwards under the driving of the transmitter; the first receiving antenna and the second receiving antenna respectively receive echo signals reflected by the ground, and the two paths of echo signals are sent to the data processing unit after being subjected to frequency mixing conversion by the receiver; and the data processing unit converts the two paths of difference frequency signals subjected to frequency mixing conversion into digital signals, and calculates the ground angle of the aircraft by calculating the phase difference of the two paths of difference frequency signals. The method has the advantages of high angle measurement precision, good real-time performance and the like.

The application discloses a terahertz mixer, comprising: a radio frequency input waveguide, a local oscillator input waveguide, a local oscillator filter and an intermediate frequency output waveguide, wherein the intermediate frequency output waveguide comprises a built-in fin line transition structure and a Schottky diode pair; one end of the fin line transition structure is connected with the radio frequency input waveguide, the other end of the fin line transition structure is connected with the local oscillator filter, the Schottky diode pair is connected with one side of the fin line transition structure and connected with an intermediate frequency output port of the intermediate frequency output waveguide; after the local oscillator signal is filtered by the local oscillator filter, the local oscillator signal is transmitted to the fin line transition structure, the radio frequency signal and the local oscillator signal are loaded into the Schottky diode pair through the fin line transition structure for frequency mixing, and the intermediate frequency signal is output through the intermediate frequency output port. In this case, the fin line transition structure simultaneously carries the radio frequency signal and the local oscillator signal, which can realize spatial superposition and power efficient injection of the signals, and has good impedance matching characteristics.

The invention provides a W-band sixteen-channel chip circuit model, and relates to the technical field of radio frequency integrated microsystems. The model comprises an up-conversion frequency mixing circuit, a down-conversion frequency mixing circuit and sixteen channel circuits connected in parallel, and each channel circuit comprises two branch circuits connected in parallel. Wherein one branch is sequentially connected in series with a low-noise amplification circuit, a first six-bit numerical control phase shift circuit, a first driving amplification circuit, a five-bit numerical control attenuation circuit and a second driving amplification circuit, and the other branch is sequentially connected in series with a first power amplification circuit, a second six-bit numerical control phase shift circuit and a second power amplification circuit. The sixteen channel circuits are all connected to an input port of the radio frequency switch circuit S. The up-conversion frequency mixing circuit and the down-conversion frequency mixing circuit are respectively connected with two output ends of the radio frequency switch circuit S. According to the method, the design speed of a complex circuit or system can be increased, and a priori condition is provided for research of a large-scale complex network.

The invention belongs to the technical field of chip algorithms, and particularly relates to a circular array beam forming method and system based on a domestic FPGA. Comprising the following steps: receiving multiple paths of array element signals, and performing frequency mixing and filtering to obtain baseband I / Q data; the base band I / Q data is unpacked to be distributed and stored in a plurality of distributed memories in an FPGA (Field Programmable Gate Array) processing unit; the method comprises the following steps: reading baseband I / Q data of a plurality of channels and corresponding phase shift coefficients in parallel, and carrying out multiplication, accumulation, summation and modulo operation to generate data of a beam point; repeating the calculation step of generating the beam point data by updating the phase shift coefficient so as to generate beam domain data; reordering the calculated sequence of the beam domain data, and adjusting the output sequence of the beam domain data; the method has the advantages of being high in processing speed, high in anti-noise capacity and the like on the basis of meeting domestic substitution.