1524 results about "Signal frequency" patented technology

The invention relates to the technical field of semiconductors, and discloses a full-temperature-zone polynomial digital temperature compensation method and system based on an SOI chip, and the method comprises the steps: obtaining the temperature frequency data of a preset temperature zone of a target SOI chip, fitting a full-temperature-zone curve, extracting a critical point of the temperature zone, dividing a segmented compensation interval according to the critical point, and obtaining the temperature frequency data of the preset temperature zone of the target SOI chip; the method comprises the following steps: calculating frequency drift amounts under different voltages to construct a full-automatic test framework, acquiring an environment temperature parameter and an instantaneous temperature value by using the framework, analyzing a temperature compensation vector of a segmented compensation interval, further monitoring a signal frequency interval output by a chip, extracting a phase noise parameter, calculating a frequency offset error amount with a preset value, and calculating the frequency offset error amount. And analyzing an error source, optimizing a polynomial compensation order, and collecting temperature drift suppression data to generate a full temperature region compensation report. According to the invention, the performance stability of the chip in a complex environment can be improved.

According to the 5G portable WiFi signal enhancement method and system provided by the invention, surrounding environment data are collected through an environment sensing sensor, and a device placement scheme is optimized in combination with a deep learning algorithm, so that the signal coverage range is expanded; the strategy of dynamically adjusting the transmitting power, the signal frequency and the modulation mode can optimize the signal strength according to the environmental change; interference signals are analyzed through quantum calculation, null is formed through the beam forming technology, interference signal receiving is effectively restrained, and the signal strength in the target direction is enhanced. In combination with the Internet of Things technology, uploading equipment state data to an edge server in real time for big data analysis, and pushing a personalized signal enhancement scheme according to different user use environments; through precise placement guidance and a dynamic frequency band switching strategy, a user can enjoy smoother network connection in a use process, and good signal quality is ensured to be kept in a complex environment. According to the invention, not only can the signal quality of 5G portable WiFi be improved, but also more intelligent and personalized network experience can be provided for users.

The invention provides a multi-band radio frequency power amplifier dynamic range adaptive test method and a system thereof. The method comprises the following steps: acquiring an output signal frequency spectrum of a tested radio frequency power amplifier, extracting characteristic frequency points including a center frequency and a bandwidth, matching the characteristic frequency points with a preset frequency band database, and automatically loading a test scheme of a corresponding frequency band. According to the method, the frequency bands are automatically matched through spectrum sensing, the test scheme is loaded, the multi-frequency-band characteristics can be rapidly adapted without manual parameter configuration, index missing test is avoided, and the switching efficiency is improved; dynamically optimizing test parameters by using a genetic algorithm, and accurately capturing a nonlinear distortion critical point while balancing coverage and efficiency; by combining multi-dimensional signal analysis and a deep learning model, the problem of missing detection of traditional single-domain analysis is solved, and the abnormal signal recognition capability is remarkably enhanced; through linear model correction, impedance dynamic matching and index threshold iteration, full automation and high precision of the test are realized, the environmental interference influence is effectively reduced, and a self-adaptive test system is constructed.

The invention discloses a system and method for classifying and recognizing epilepsy in electroencephalogram signals based on a time sequence. The system comprises a cross-domain mixed self-supervised learning module, a multi-scale electroencephalogram feature learning module, an epileptic seizure guided self-attention learning module and a classifier. The cross-domain hybrid self-supervised learning module comprises a time domain context prediction task unit, a channel information reconstruction task unit and a frequency spectrum masking identification task unit; the cross-domain hybrid self-supervised learning module reconstructs an input electroencephalogram signal according to a time domain, a space domain and a frequency domain to obtain an electroencephalogram representation model; the time domain context prediction task unit is used for capturing dynamic change characteristics before and after epileptic seizure by learning a time domain evolution rule of electroencephalogram signals; the channel information reconstruction task unit is used for reconstructing missing electroencephalogram signal channel data and enhancing spatial information representation of an electroencephalogram representation model; the frequency spectrum masking identification task unit trains the electroencephalogram characterization model to characterize epilepsy nerve oscillation through a random masking part electroencephalogram signal frequency component in a frequency domain; the multi-scale electroencephalogram feature learning module captures local and global level epilepsy features of an electroencephalogram representation model through different resolutions to obtain a first epilepsy electroencephalogram feature model; the epileptic seizure guided self-attention learning module optimizes the first epileptic electroencephalogram feature model by fusing time sequence and spatial features to obtain a second epileptic electroencephalogram feature model; and the classifier classifies and outputs the electroencephalogram features of the second epileptic electroencephalogram feature model based on the long short-term memory network to determine whether the epileptic seizure occurs. The invention provides an efficient, accurate and robust solution for automatic detection and clinical auxiliary diagnosis of the epileptic seizure.

The invention relates to a digital lock-in amplifier based on a frequency adaptive technology and a weak signal acquisition system and method, and the system comprises a front-end signal processing module which is used for obtaining a weak signal to be detected; the frequency self-adaptive tracking module is used for performing fast Fourier transform on the frequency of the weak signal to be measured to obtain the position of the maximum spectral line so as to synthesize a frequency control word, further generate a local reference signal and simultaneously adjust the coefficients of a low-pass filter and a loop filter and the series adjustment mode of a carrier synchronization ring; the multi-rate narrow-band low-pass filter module is used for multiplying the digital signal by a local reference signal and then carrying out filtering and down-sampling on a high-frequency signal to obtain a plurality of mutually orthogonal difference frequency components; the vector operation module is used for carrying out vector operation on the plurality of mutually orthogonal difference frequency components to obtain the phase and the amplitude in the weak signal to be measured; and the man-machine interaction module is used for displaying and storing the phase and the amplitude in the weak signal to be detected.

The invention discloses a distributed photovoltaic access power distribution network relay protection analysis method and system, and belongs to the technical field of photovoltaic grid connection, and the method specifically comprises the steps: injecting a dynamic resonance detection signal at the AC side of a current converter of a photovoltaic grid-connected system, and enabling the frequency to be matched with the natural resonance frequency of a target section; analyzing the energy focusing effect of the dynamic resonance detection signal in the power distribution network, and generating a resonance energy distribution map; when the energy density of a certain section in the resonance energy distribution map exceeds a preset threshold value, the photovoltaic output current waveform is adjusted to be a discontinuous waveform containing periodic intermittent cutoff; based on the reflection delay difference of the waveform in the fault section, constructing a space-time mapping model of a fault point, and analyzing and determining a fault position; according to an output result of the space-time mapping model, controlling a photovoltaic side circuit breaker and a power grid side relay to execute a selective tripping action based on waveform phase synchronization; according to the invention, the sensitivity and reliability of distributed photovoltaic access power distribution network relay protection are improved.

The invention discloses a sparse cloth double-array element multi-frequency ambiguity resolution interference angle measurement method and system, relates to the technical field of radar measurement, realizes design of a multi-frequency signal frequency selection criterion, and further realizes non-ambiguity and high-precision angle measurement of all angles in an angle range required by engineering. According to the technical scheme, a physical baseline length and a reference frequency are set according to a layout space; deriving a plurality of signal carrier frequency design criteria according to the Chinese remainder theorem; calculating the carrier phase difference of the double-array-element receiving signals under different signal carrier frequencies; and reconstructing the congruence equation set, and solving the congruence equation set to solve ambiguity so as to obtain a target angle estimation value.

The invention belongs to the technical field of unmanned aerial vehicle full-aviation electromagnetic detection, and particularly relates to a full-aviation frequency domain electromagnetic emission system and a control method. A broadband frequency mixing and matching circuit is connected in series between an H-bridge power inverter and an emission coil of an unmanned aerial vehicle electromagnetic emission system; the broadband mixing and matching circuit comprises a first resonance unit formed by connecting a fixed capacitor and an adjustable inductor in parallel and a second resonance unit formed by connecting a fixed capacitor and an adjustable inductor in parallel, and the first resonance unit and the second resonance unit are connected in series. The adjustable inductor is matched with the dynamic impedance of the inductive load by adjusting the inductance value, and the broadband frequency mixing and matching circuit can adjust the impedance in real time, so that the matching of different resonant frequencies is realized, and the frequency range of a matching signal can be obviously widened.

A data and clock recovery circuit, a receiving apparatus, a circuit system, a vehicle-mounted device, a vehicle, and a data and clock recovery method are provided. The data and clock recovery circuit includes a sampler, a phase detector, a multi-order filter, a frequency change detection circuit, and a selector. The sampler is configured to sample an input signal based on a multi-order filtered signal to generate a sampled signal. The phase detector is configured to determine a phase difference in the sampled signal based on the sampled signal. The multi-order filter is configured to generate the multi-order filtered signal based on the phase difference. The frequency change detection circuit is configured to determine a frequency change direction of a spread spectrum clock in the input signal by using the phase difference.

The invention discloses an adaptive equalization method for combined compensation of carrier frequency offset and channel linear damage. The adaptive equalization method specifically comprises the following steps: taking data subjected to matched filtering, clock synchronization, orthogonality and normalization as input signals; for an input signal, using the filter linear damage compensation weight vector and the frequency offset compensation weight coefficient to obtain output data of the filter; obtaining an expected value of filter output data, and calculating to obtain a theoretical error value of adaptive equalization; and obtaining a filter weight vector used for next adaptive equalization according to the theoretical error value. The adaptive equalization method for combined compensation of carrier frequency offset and channel linear impairment is suitable for a coherent optical transmission system, uses an adaptive equalizer to compensate signal frequency offset and channel linear impairment at the same time, does not need an additional frequency offset estimation algorithm, meets the advantages of multiple rates and multiple modulation formats, and is high in convergence speed and high in robustness. And the calculation complexity is low.

The invention relates to the technical field of spectral analysis, and discloses a visible spectrum noise reduction and heavy metal ion detection method, which comprises the following steps: reacting a water sample to be detected with a color developing agent to generate a color developing system, obtaining a gray spectrum signal through optical imaging equipment, carrying out variational mode decomposition, optimizing the signal by adopting singular value decomposition, and calculating the noise of the heavy metal ions. And determining an optimal reconstruction order by using a particle swarm optimization algorithm and reconstructing a signal, finally extracting a feature value from the denoised spectral signal, and predicting the type and concentration of metal ions through a neural network model. Spectral global / local features are modeled through cooperation of multi-head self-attention and learnable position coding, signal frequency-time domain cross-modal fusion is realized in combination with variational mode decomposition and cross attention, training parameters are dynamically optimized by innovatively adopting a reinforcement learning strategy, classification and regression tasks are self-adaptively balanced based on a gradient diversity reward mechanism, and frequency-time domain cross-modal fusion is realized. And finally, dual precision improvement of ion type identification and concentration prediction and model robustness enhancement are realized in a complex noise scene.

The invention relates to a power line network unknown port and branch discovery method and device and computer equipment. The method comprises the following steps: determining the number of unknown ports on a target line and the corresponding branch length according to the frequency response of a sweep frequency signal between a transformer substation and a target communication node; according to the frequency response of the sweep frequency signal, determining multipath parameters from the transformer station to the self-transmitting and self-receiving and from the transformer station to the target communication node; determining a first port closest to the substation according to the multipath parameter and the branch length, and determining a multipath channel response caused by the first port; and updating the frequency response of the sweep frequency signal according to the multipath channel response, and re-determining a first port closest to the transformer substation according to the updated frequency response of the sweep frequency signal until the number of unknown ports on the target line is zero. By adopting the method, the power line network topology can be accurately constructed.

The embodiment of the invention provides a method for realizing long-distance signal transmission under the condition of a porous medium in a goaf. The method comprises the following steps: selecting a proper signal frequency range based on the physical characteristics of the porous medium in the goaf; designing a corresponding signal modulation mode according to the selected signal frequency range; the stability of a signal propagation path is enhanced through a relay node deployed in the goaf; modulation parameters are dynamically adjusted based on the signal quality fed back by the relay node to optimize the transmission effect. Through the scheme of the embodiment of the invention, the problem of how to optimize and select the signal frequency so as to solve the problem of too fast signal attenuation in the porous medium can be solved, and meanwhile, the problem of how to regulate and control the dielectric property of the transmission path so as to solve the delay problem caused by signal refraction and reflection can be solved; and the problem of bit error rate increase in long-distance transmission can be solved by adjusting the signal coding mode.

The invention relates to the technical field of mechanical vibration and fluid excitation coupling effect analysis, in particular to a runner crown modification pressure pulsation amplitude measurement method, which comprises the following steps of: extracting pressure gradient distribution and cavitation phase change characteristic parameters of a runner surface through fluid dynamics simulation; targeted arrangement of a high-frequency pressure sensor array in a vortex core area, a boundary layer separation critical position and a modification structure mutation area is guided, and the signal acquisition precision is improved by adopting an annular encryption and axial equal-interval arrangement strategy. And establishing a dynamic error feedback mechanism of actual measurement and simulation. And verifying an abnormal frequency band proportion through frequency domain kurtosis and analyzing envelope spectrum harmonic waves, and screening a modification parameter combination with the pressure pulsation amplitude decreasing to reach the standard and stable frequency band distribution. According to the method, the problem of measurement errors caused by multi-source high-frequency noise and effective signal frequency domain aliasing is solved, a high-precision quantification basis is provided for runner modification optimization, and the method is suitable for the field of mechanical system dynamic characteristic testing.

The invention discloses an InSAR (Interferometric Synthetic Aperture Radar) phase filtering method based on a plurality of interferograms, which comprises the following steps of: preprocessing acquired main and auxiliary SAR images to obtain the plurality of InSAR interferograms; dividing the plurality of InSAR interferograms into square interferogram patches along the azimuth direction and the distance direction; converting each interferogram patch from a spatial domain into a frequency domain signal, and constructing a corresponding frequency spectrum amplitude diagram; using a K-means clustering method to cluster and extract an initial low-pass filter in the spectrum amplitude diagram, and constructing a phase filter together with a Kaiser window function; the frequency domain signals of the interferogram plaques pass through a phase filter, the signal frequency band power is reserved, the noise at the high-frequency position is filtered out, meanwhile, the noise at the low-frequency position is filtered out through smoothing operation, and the filtered frequency domain signals are obtained; and the filtered frequency domain signals are converted to a spatial domain, filtered interferogram patches are obtained and spliced, and a filtered InSAR interferogram is obtained. The method is beneficial to popularization and promotion of the development of the current time sequence InSAR interferometry technology and the application in engineering.

The invention relates to the technical field of integrated circuits, in particular to a charge pump phase-locked loop circuit, a radar and a charge pump phase-locked loop locking control method.The circuit comprises a charge pump, the charge pump comprises a first branch circuit, a second branch circuit, a third branch circuit and a fourth branch circuit, the frequency sweeping state refers to the state when the frequency of the signal output by the phase-locked loop is linearly changed; the at least one second branch is connected to the first branch under the condition that the hopping amplitude of the frequency of the signal output by the phase-locked loop is greater than or equal to a preset amplitude threshold value so as to increase the magnitude of the current output by the charge pump, and is disconnected with the first branch when the phase-locked loop enters a frequency sweeping state; the circuit can effectively shorten the locking time of the phase-locked loop when the phase-locked loop has relatively large frequency hopping, and is beneficial to improving the response speed and performance of a system.

The invention relates to the technical field of data communication, in particular to a WiFi (Wireless Fidelity)-based data communication method and system. The method comprises the following steps: acquiring a routing WiFi (Wireless Fidelity) 6 networking control authority, acquiring a signal frequency band state and identifying a frequency band load state; then, the load state is converted into a spectrogram, and throughput attenuation simulation and adjacent channel interference risk quantification are carried out; then, fitting a network congestion increment index according to the data packet loss risk and throughput attenuation data, and performing channel frequency band planning and OFDMA subcarrier allocation optimization according to the network congestion increment index; and finally, designing a WiFi (Wireless Fidelity) data communication strategy, and sending the WiFi data communication strategy to a control center to implement the optimized data communication method. According to the invention, the data communication technology is optimized, so that the data communication technology is more perfect.

The invention relates to the technical field of partial discharge detection, in particular to a partial discharge detection method and system for a high-low voltage switch cabinet, and the method comprises the steps: obtaining electromagnetic wave signals and power system voltage data of each sensor position in real time; acquiring a partial discharge period in each detection window according to the electromagnetic wave maximum value of all the sensors in each power frequency period in each detection window, the distance between the electromagnetic wave maximum value and the voltage wave crest and the voltage wave trough of the power system, and the electromagnetic wave signal difference between the sensors; and according to the dispersion degree of the electromagnetic wave maximum values of all the sensors under each partial discharge period in each detection window, the electromagnetic wave signal frequency domain energy of each partial discharge period and the proportion of the partial discharge period in each detection window, obtaining the existence confidence of each detection window, and judging whether partial discharge exists under the current detection window or not. According to the invention, by analyzing the distinguishing characteristics of the partial discharge and the electromagnetic interference in the electromagnetic wave signals at multiple positions, the detection precision of the partial discharge is improved.

The invention relates to the technical field of energy conservation and environmental protection, in particular to an industrial boiler combustion oscillation modal suppression system and a method thereof, and constructs a system which is highly intelligent, high in adaptability and remarkable in suppression effect by fusing innovative technologies such as multi-dimensional perception, intelligent identification, active suppression and adaptive optimization. The data acquisition module accurately captures hearth temperature, flame video and sound pressure signals; the signal processing module deeply analyzes and extracts oscillation modes of a temperature field and a flame area, and analyzes a sound pressure signal frequency spectrum through short-time Fourier transform; the mode identification module accurately identifies the combustion oscillation mode and determines the characteristic frequency and amplitude of the combustion oscillation mode; the suppression control module generates an infrasonic wave intervention signal to form an anti-phase sound field so as to effectively suppress oscillation; the fuel adjusting module adjusts the opening time sequence of the gas nozzle according to the instruction, and fuel supply is optimized. According to the system, the operation stability and heat efficiency of the boiler are remarkably improved, NOx emission is greatly reduced, and powerful technical support is provided for clean and efficient operation of the industrial boiler.

The invention relates to a phase-sensitive optical time domain reflectometer based on a parallel frequency division multiplexing sequence. Continuous laser is divided into a local path and a detection path through an optical coupler; the local path is input to the polarization coherent receiving module, the detection path is converted into a pulse laser sequence with intensity modulation through a light intensity modulator driven by a radio frequency signal provided by the signal generation circuit module, and the radio frequency signal is composed of two frequency division multiplexing sequences with difference; the pulse laser sequence enters the sensing link to be measured to generate Rayleigh backscattered light, and the Rayleigh backscattered light and local continuous laser are subjected to beat frequency coherent receiving through a circulator; and the signal acquisition circuit is used for sampling and analyzing the interference signal, and performing frequency domain comparison on an interleaving result of the two frequency division multiplexing pulse sequences to eliminate a harmonic frequency and retain a real strain signal frequency. Compared with the prior art, the non-harmonic strain signal measurement is realized, the high-frequency response performance and the high-precision strain measurement capability are excellent, and meanwhile, the long-distance coverage capability is also realized.

The invention provides a speech recognition accuracy evaluation statistical method, which comprises the following steps: acquiring current underwater depth, helium-oxygen mixed gas density, original speech waveform and respiratory resistance, analyzing to obtain waveform change amplitude and gas density change amplitude, and recognizing main frequency components in the original speech waveform; combining the corrected voice waveform with the helium-oxygen mixed gas density and the respiratory resistance to evaluate the stability degree of the sound production gas flow, and determining audio sample classification according to the stability degree of the sound production gas flow; and classifying and grouping the audio samples according to a preset depth interval so as to adapt to acoustic environment changes of different depths, and identifying a voice signal frequency characteristic offset rule of different underwater depth groups so as to obtain voice identification standards for different underwater depth levels.

The invention provides an SI simulation optimization method and device for a PCB, and the method comprises the steps: selecting a simulation boundary according to the via hole type, the board thickness and the signal frequency of the PCB, and carrying out the one-time simulation according to the simulation boundary, and obtaining an S parameter; gradually expanding the simulation boundary by adopting a progressive method, carrying out secondary simulation, and determining an optimal boundary range when the S parameter change of two adjacent simulations is smaller than a preset convergence threshold value; electromagnetic field distribution parameters are calculated in the optimal boundary range, and an area with concentrated electromagnetic energy in the electromagnetic field distribution parameters is set as an area to be improved; a passive device is arranged in the to-be-improved area, the position and parameters of the passive device are iteratively optimized, and device layout parameters are obtained; and optimizing and adjusting the PCB based on the device layout parameters.

The invention relates to the field of unmanned aerial vehicle communication, in particular to an unmanned aerial vehicle communication frequency band monitoring method and interference method.The method comprises the following steps that 1, background noise signals of a full frequency band are collected, Fourier transform is conducted on the collected background noise signals, and a signal frequency band with energy exceeding a preset threshold value is extracted; step 2, acquiring each signal frequency band with energy, and performing adaptive IMF component decomposition on each signal frequency band with energy; 3, screening the IMF components according to the impact energy of the IMF components, and performing signal reconstruction on the screened IMF components; and step 4, inputting the reconstructed signal into the neural network model for rule analysis, and generating a risk coefficient of existence of communication in a signal frequency band according to the rule analysis.

The invention is suitable for the technical field of data processing, and provides a new energy station voltage and frequency coupling cooperative control performance online evaluation method, which comprises the following steps: acquiring a three-phase voltage signal, a frequency signal, a unit output power signal and a power grid dispatching instruction signal of a new energy station grid-connected point, and calculating a voltage and frequency coupling characteristic matrix; performing collaborative quantitative analysis to generate a collaborative parameter matrix; performing control performance evaluation on the collaborative parameter matrix based on the collaborative evaluation network structure to generate collaborative evaluation parameters; constructing a dynamic coupling constraint function, and calculating to obtain a collaborative stability boundary representing the operation state of the station; and dynamically correcting the collaborative evaluation parameters to generate a station control performance optimization sequence. And the safety, the stability and the electric energy quality of the operation of the new energy station are effectively improved.

The invention discloses an analog Doppler frequency shift and arrival angle measuring device and method based on Rydberg atoms, and in the aspect of DFS measurement, the device performs beat frequency on two signals to obtain an intermediate frequency signal frequency which is a DFS value; the device calculates the AOA of the echo signal by measuring the phase difference of the echo signal at two different positions in the cesium gas pool. According to the invention, simultaneous measurement of DFS and AOA can be realized, and the scheme has the advantages of simple structure, stable system, multifunction, anti-interference and the like, and has great application prospects in electronic reconnaissance and countermeasure systems and the like.

The invention relates to the technical field of radio frequency, in particular to a radio frequency conversion assembly, and the assembly comprises a baseband processing unit which employs a millimeter wave SoC chip and is used for generating and processing an initial transmitting signal of 79-81GHz and an initial receiving signal of 79-81GHz; the frequency conversion unit comprises an up-conversion subunit and a down-conversion subunit, and the local oscillation synthesis unit is used for generating and providing a local oscillation signal with a fixed frequency; the mode switching and processing system is used for selectively performing down-conversion processing on the echo signal or a target radio frequency signal from an external non-cooperative irradiation source in two working modes and then transmitting the echo signal or the target radio frequency signal to the baseband processing unit; the working mode comprises an active mode and a passive mode.

The invention relates to the field of solid waste crushing equipment, and discloses a solid waste crushing equipment working state monitoring method and system, and the method comprises the steps: collecting a current signal, a vibration signal and a sound signal during the operation of solid waste crushing equipment; when the duration of the peak value of the current signal is smaller than a preset duration threshold value, the impact frequency characteristic of a first vibration frequency band exists in the frequency spectrum of the vibration signal, and the decibel peak value of the sound signal in the preset first frequency band is greater than a second preset threshold value, judging that the current signal is instantaneous load fluctuation; when the duration of the peak value of the current signal is greater than a preset duration threshold value and the vibration signal frequency spectrum presents continuous abnormal fluctuation with the period greater than a first preset duration, determining that a continuous overload fault occurs; if so, judging that the load fluctuates instantaneously; if yes, a feeding mechanism of the solid waste crushing equipment is controlled to reduce the feeding speed, and first prompt information is generated. According to the technical scheme, the monitoring accuracy is improved.

The embodiment of the invention provides a dual-frequency base station antenna, and belongs to the technical field of antenna equipment, the dual-frequency base station antenna comprises a grounding plate, two dielectric substrates are laminated on the grounding plate, each dielectric substrate is correspondingly provided with a radiation unit, and the radiation signal frequency bands of the two radiation units are different; the radiation unit comprises a radiation patch and a metal through hole array which are arranged on the dielectric substrate, the radiation patch is a fan-shaped patch, the metal through hole array is arranged around the arc-shaped edge of the radiation patch, and the metal through hole array, the grounding plate, the dielectric substrate and the radiation patch jointly form a substrate integrated waveguide resonant cavity; the substrate integrated waveguide resonant cavity is configured to couple and excite the radiation patch after being externally excited so as to radiate a signal of a preset frequency band through the radiation patch. The dual-frequency base station antenna provided by the embodiment of the invention has excellent pilot frequency isolation performance, and can realize bandwidth expansion and radiation optimization effects.

The invention discloses a laser scanning system, and belongs to the technical field of laser signal processing. The system comprises a laser emission and control module, a scanning device, a receiving device, a signal processing module and a self-adaptive learning module. And the signal processing module extracts the instantaneous frequency of the beat signal through Fourier transform and Hilbert transform, and dynamically adjusts the input voltage based on an iterative algorithm optimized by the adaptive learning module to realize linearization correction of the beat signal frequency and a nonlinear mapping linearization interpolation scheme. The adaptive learning module stores historical correction data, dynamically optimizes parameters such as step length and convergence conditions of an iterative algorithm by using a machine learning method, and improves the adaptability and correction precision of the system in a complex environment. According to the method, full-closed-loop intelligent control from signal acquisition and processing to parameter optimization is realized, and the method has the characteristics of high precision, strong robustness and low manual intervention, and is suitable for the fields of laser radar, three-dimensional scanning, precise distance measurement and the like.

The invention provides a novel multi-frequency and multi-mode coverage system, and relates to the technical field of mobile communication. Comprising a signal receiver which is provided with a receiving module supporting reception of signals of multiple frequency bands at the same time, and is responsible for receiving and filtering radio frequency signals of different frequency bands, ensuring the purity of the signals, and screening the signals by using a multi-dimensional signal feature self-adaptive dynamic enhancement mechanism; the signal feature analysis module obtains key signal feature information of a corresponding frequency band signal from the received radio frequency signal through the coupler based on a signal energy envelope detection mode; the uplink and downlink signal processing circuit performs signal amplification processing on a specific signal system, a specific signal frequency band and a specific signal bandwidth in a targeted manner according to the characteristic information, and transmits the processed signal to a target area through the signal transmitter, and the signal transmitter comprises a transmitting module supporting transmission of signals of a plurality of frequency bands. Signals are transmitted for different frequency bands through the passive antenna, and filtering processing is carried out before transmission, so that full-frequency-band coverage is realized.