49 results about "Linear phase" patented technology

The invention relates to the technical field of optical detection, and discloses an object surface three-dimensional topography measurement method based on optical interference, which comprises the following steps: acquiring a mixed time domain interference signal sequence in an axial scanning process; extracting seed pixels and constructing a spatial topology connectivity feature matrix; introducing fractional Fourier transform, and constructing a joint decoupling objective function containing a frequency domain nonlinear phase distortion evaluation index and a time domain physical invariant evaluation index; executing multi-stage optimization for the seed pixels, and locking a global optimal rotation angle; array self-adaptive decoupling is executed in combination with the spatial topology connectivity feature matrix, and an optimal rotation angle matrix is generated; and performing signal decoupling and reconstruction on the mixed signal, and extracting the absolute surface height of each pixel point to generate three-dimensional shape data. According to the invention, through multi-dimensional joint decoupling and spatial prior constraint, the problem of phase decoupling caused by film interference aliasing is solved, and the calculation overhead of a large-pixel array is reduced while the measurement precision is improved.

The invention relates to the technical field of broadband signal synthesis and high-speed digital-to-analog conversion, in particular to an oversampling-based real-time frequency interleaving digital-to-analog conversion system aliasing suppression method and system, and aims to solve the problem of spectrum aliasing caused by non-ideal characteristics of a digital sub-band decomposition filter and an analog filter under a real-time architecture of the system. In the invention, the sub-band decomposition is completed by adopting the linear phase complementary filter bank, so that distortion introduced by a transition band of a digital filter is avoided; by restraining system parameters such as passband and stopband frequencies and local oscillation frequency of a sub-band decomposition filter, a protection band is set by an oversampling mechanism, a frequency margin is reserved for a transition band of the filter, and aliasing components are suppressed. According to the method, extraction aliasing of a digital domain and mirror image aliasing of an analog domain are avoided at the same time from the system architecture, the frequency spectrum purity of output signals is improved, the method is suitable for a real-time system for processing continuous data streams, and technical support is provided for achieving a high-performance broadband signal source.

The invention discloses a method and a system for optimizing a metering front end of an intelligent electric meter. The method comprises the following steps of: setting an anti-aliasing network with a near-linear phase at the front end of a metering channel and synchronously sampling; determining a range switching window based on zero crossing or a preset voltage change rate, executing automatic range switching in the window, and performing overlapping sampling and digital splicing on samples before and after switching; determining a rectification conduction empty window based on the rectification conduction prediction, suspending sampling in the empty window, and compensating a missing sample; injecting a reference signal into the channel at the calibration injection window, obtaining a correction coefficient according to response, and performing online correction; the three types of windows are not overlapped and are uniformly scheduled by a synchronous time sequence; and completing power and energy calculation according to the corrected voltage and current sequence. The system comprises an anti-aliasing network unit, a range control unit, a rectification conduction detection unit, an air window door control unit, an injection and online correction unit, a time sequence synchronization unit, a metering calculation unit and the like. According to the invention, low-distortion, wide-range and consistent metering output can be realized in practical application.

This system is directed to an orbital angular momentum generator which can include an AOD; a beam shaping optic assembly; a log-polar optic; a Fourier lens; and, wherein the orbital angular momentum generator is configured to produce pulse shaping according to the application of a quadratic waveform chirp that corresponds to one or more OAM modes. The system can include an ultrashort pulsed laser; a log-spiral transformation assembly; an AOD; an ellipse generator; a λ / 2 plate; and, wherein the optical system is configured to provide for multiple coherent spiral beams with control of amplitude and relative phase. The system can include an ultraviolet orbital angular momentum generator comprising: a femtosecond pulsed laser; a crystal configured to provide a collinear phase-matching; and can provide a UV OAM source for imaging with high resolution and quantum information. The AOD can be replaced with a scanning mirror and configured to add a linear phase gradient.

The application belongs to the field of transformers, and discloses a linear phase-shifting transformer equivalent circuit modeling and performance parameter obtaining method, analyzes the electromagnetic relationship between the primary side winding and the air gap when the linear phase-shifting transformer is in steady-state operation, and Maxwell equations of the linear phase-shifting transformer; based on the theory of one-dimensional field, the equivalent circuit of the linear phase-shifting transformer is established and solved when the longitudinal edge effect is considered. The performance parameter obtaining method is also disclosed, which comprises: solving the established equivalent circuit model to obtain the resistance and leakage reactance of the primary side winding, the excitation reactance, and the secondary side winding resistance; and calculating the performance parameters of the linear phase-shifting transformer based on the equivalent circuit solving result. The application considers the actual situation of the transformer in electromagnetic analysis, the model is more accurate, the calculation precision is high, the winding loss, efficiency and voltage regulation rate and other performance parameters of the transformer can be quickly and effectively calculated, the application is relatively convenient in actual calculation and analysis, and has high practical value.

The application relates to the field of backscatter technology and discloses a single-receiver WiFi backscatter communication method and system, which comprises the following steps: a tag receives OFDM symbols from ambient WiFi signals, a linear phase factor corresponding to a tag-related cyclic shift value is applied to only the middle part of a data load, and the OFDM symbols of a reflection signal are reconstructed based on the middle part of the modulated data load; a receiver extracts the modulated part from the received OFDM symbols of the reflection signal, performs frequency domain inverse shift compensation on each candidate cyclic shift value, obtains a reconstructed data load based on the obtained compensated spectrum, calculates the correlation score between the power spectrum of the reconstructed data load each time and a binary template predefined based on the position of the empty subcarrier, decodes the cyclic shift value, and recovers the corresponding tag data. The application can realize a high data throughput without sacrificing OFDM compatibility.

The invention relates to a real-time digital audio filtering system and an implementation method thereof. The real-time digital audio filtering system is composed of a high cut-off filter bank module, a low cut-off filter bank module, a subtracter module, a sampling rate synchronous interpolator module and a sampling rate converter module. Wherein the high cut-off filter bank and the low cut-off filter bank are respectively composed of a plurality of stages of low-pass filtering units, and each stage of low-pass filtering unit is composed of a plurality of FIR low-pass filters; and the sampling rate synchronous interpolator is used for synchronizing the frequencies of the output signals of the high and low cut-off filter banks. Different bandwidth requirements can be met only by designing a small number of low-pass filters, and bandwidth adjustment is flexible and convenient; the used filters are low-order FIR (Finite Impulse Response) filters, so that the time delay of the system is less, the operand is small, the output signal is linear phase and has no distortion, and meanwhile, the method also has good universality and can be applied to other real-time digital audio systems after the cut-off frequency of the filters is simply adjusted.

A method for reducing inter symbol interference (ISI) and inter carrier interference (ICI) in transmissions between a sender and a recipient within a wireless communication network. For at least one multicarrier symbol comprising a first subcarrier modulated with an original reference signal and multiplexed with a second subcarrier modulated with an original payload signal. The method includes applying a multiple symbol shift configuration on at least a second multicarrier symbol adjacent to the first multicarrier symbol by repeating the original reference signal and the original payload signal in the second multicarrier symbol on respective subcarriers and applying a linear phase shift to each repeated reference signal and payload signal. The same linear phase shift is used for both the repeated reference signal and the repeated payload signal.

The invention discloses a broadband achromatic programmable electromagnetic camouflage device based on a fluid access metasurface. The broadband achromatic programmable electromagnetic camouflage device comprises the fluid access metasurface composed of a plurality of periodically arranged super units. Each super unit comprises a plurality of units arranged in a matrix; each unit comprises a microfluid channel layer and a solid metal layer, and the microfluid channel layer is located above the solid metal layer; the microfluid channel layer is connected to an external driving system through the injection and discharge port, and the external driving system is used for injecting liquid metal or dielectric liquid into the microfluid channel layer; when the microfluid channel layer is filled with liquid metal, the unit is in a first working state; and when the micro-fluid channel layer is filled with the dielectric liquid, the unit is in a second working state. According to the invention, linear phase dispersion control can be realized in a broadband, and it is ensured that the generated false target echo keeps high fidelity in a time domain when facing a broadband pulse radar.

This invention relates to the field of signal processing technology and provides a ground clutter frequency domain suppression method based on correlation spectrum. Its key feature is the use of phase information from the autocorrelation spectral density of weather radar echo signals to identify and suppress ground clutter signals. The method includes: adaptively selecting an optimal data window function based on the clutter-to-noise ratio of the weather radar echo signal and performing power-preserving processing; calculating the autocorrelation spectral density and power spectral density, and effectively distinguishing clutter from broadband weather signals using the local deviation characteristics of the autocorrelation spectral density relative to the ideal linear phase, thereby performing clutter identification and filtering. Based on the autocorrelation spectral density after filtering out ground clutter, an inverse transform is performed to calculate the autocorrelation function, completing the time-domain estimation of the weather radar detection variables. This invention effectively solves the problem that traditional ground clutter suppression methods cannot accurately identify and eliminate ground clutter mixed in with weather signals.

The application belongs to the technical field of radio frequency communication, and discloses a novel wideband linear phase filter and a design method thereof. The novel wideband linear phase filter comprises a first port, a second port, and three first transmission lines connected in series between the first port and the second port. Four connection points are formed between the first port and the adjacent first transmission line, between the three first transmission lines, and between the second port and the adjacent first transmission line. Four short-circuit branch lines are connected at the four connection points one by one. An inductance circuit module is connected at one end of the connection point between the first port and the adjacent first transmission line, and connected at the other end of the connection point between the second port and the adjacent first transmission line.

The application discloses a kind of cross-scale visual ultra-precision motion measurement device and method, the device includes image sensor, aperture diaphragm, imaging lens group, coaxial light source, beam splitter, positioning platform, encoding plate and DSP and ARM integrated signal processing system.In the method, by selecting the number of linear feedback shift register and period large λ and carrying out periodic coding, after DSP and ARM signal processing system pre-processing operation to image, static random access memory is driven to carry out image caching;Two-dimensional Fourier transform is executed to cached image, and relevant linear phase processing is carried out;According to the phase data obtained by linear phase processing, the corresponding binary sequence on local image is identified;The identified local binary sequence is looked up to the binary sequence of encoding plate and positioned, and according to the phase constant of periodic phase measurement, fine positioning is carried out.

The invention discloses a radio frequency fingerprint extraction method and device, electronic equipment and a storage medium. The radio frequency fingerprint extraction method comprises the following steps: sampling a received signal, and carrying out down-conversion to obtain a baseband signal; frame synchronization is carried out on the baseband signal, carrier frequency offset compensation and phase offset compensation are carried out on the signal after frame synchronization, and a target signal is obtained; converting the target signal to a frequency domain to obtain a frequency domain representation; and according to the frequency domain representation of the target signal, a phase curvature feature is extracted as a radio frequency fingerprint, and the phase curvature feature is a second-order difference of phases between adjacent frequency points. According to the method, linear phase distortion introduced by channels can be effectively eliminated, and only nonlinear phase response caused by transmitter hardware distortion is reserved, so that robust radio frequency fingerprint extraction is realized under various channel conditions, and reliable support is provided for high-precision physical layer identity authentication.

This invention discloses a millimeter-wave wide-beam DRA, a wide-angle beam scanning phased array, and their design methods. The DRA consists of a DR and a microstrip coupling slot located directly below the DR. This invention enables the non-exciteable DRA to achieve TE by setting the dimensions of the slot and the DR. 112 The resonant frequency of the mode is close to that of the slot operating mode, and the field inside the DR will exhibit a similar behavior to that of the TE mode. 112 The field distribution of the mode forms an equivalent magnetic current parallel to the ground plane, thereby achieving wide beam characteristics in the E-plane and H-plane; moreover, arranging multiple such small-sized DRA units at equal intervals can form a linear phased array in the E-plane (H-plane), whose beam can be scanned from -72° to +72° (-65° to +65°), with a gain ripple of 2.5dB (0.5dB), and the present invention does not require any parasitic structures or additional active control circuits.

The application relates to a digital wave trap, a digital low-pass filter and a design method, a medium and an electronic device. The digital wave trap comprises a wave limit boundary anchoring unit and a wave limit zero point modulation unit which are cascaded in sequence, the wave limit boundary anchoring unit adopts a cascaded integral comb filter structure and is used for generating a first attenuation zero point at a boundary frequency of a target wave trap frequency band; the wave limit zero point modulation unit adopts a finite-length unit impulse response filter structure and is used for generating at least one second attenuation zero point in the target wave trap frequency band; and a continuous suppression band for the target wave trap frequency band is formed in the amplitude-frequency response of an output signal of the wave limit zero point modulation unit by the first attenuation zero point and the at least one second attenuation zero point. By using the digital wave trap provided by the application, a digital low-pass filter which can deeply and widely suppress power frequency interference and maintain strict linear phase and excellent low-pass characteristics can be designed without significantly increasing hardware resources and power consumption.

The present application relates to the technical field of thickness measurement, and discloses a linear dimensional measurement method for AR module thickness, comprising: obtaining a spectral interference signal and resampling to a wave number space to generate a wave number domain complex sequence; extracting a real part, an imaginary part and a first derivative term of the wave number domain complex sequence; establishing an orthogonal component set; extracting a transient phase slope by using differential mapping between the orthogonal components; determining a wave number domain group delay distribution; calling a dispersion calibration matrix to correct nonlinear deviation; converting nonlinear phase evolution into linear phase gradient; fitting the linear phase gradient to solve a physical thickness value; and bypassing arctangent calculation and phase unwrapping by establishing phase gradient mapping logic, suppressing phase jump caused by interference envelope aliasing from the dimension of physical energy distribution, improving thickness calculation stability of an extremely thin medium layer under environmental interference, and realizing physical decoupling of material dispersion characteristics and geometric dimensional parameters.

This application provides a linear phase modulation method and system based on a linear receiving array, aiming to solve the problems of traditional underwater acoustic imaging systems being complex, having low resolution, and being unable to image moving targets in real time. The method uses an angular domain bandpass filter to filter and linearly phase-modulate the echo signal of a uniform acoustic wave with the same wavefront phase as the transmitted wavefront from the transmitting transducer at the receiving array. Then, through linear superposition, it modulates the wave into a spiral wave with a linear phase to the incident angle of the plane wave in each direction. The system includes a transmitting transducer for transmitting pulses, a linear receiving transducer array for receiving echoes, and an array signal processor for executing the above modulation method. This invention requires only a single sound source and only one transmission and reception cycle to perform real-time high-resolution underwater acoustic imaging of both stationary and moving targets, significantly simplifying the system while generating spiral waves of a much higher order than existing technologies, thereby constructing high-resolution underwater acoustic images.

The invention provides a power amplification circuit, a power amplifier, a transceiving assembly and a pulse compression radar, and relates to the technical field of circuit design. The power amplification circuit at least comprises a linear phase predistortion circuit and a power amplification unit, the input end of the linear phase predistortion circuit is connected with a target signal, the output end of the linear phase predistortion circuit is connected with the input end of the power amplification unit, and the output end of the power amplification unit outputs the amplified target signal; wherein the target signal represents a signal to be amplified; the linear phase pre-distortion circuit is used for generating a nonlinear phase error opposite to the nonlinear phase error of the power amplification unit in direction. The power amplifier does not need to compromise indexes such as efficiency, power and stability, does not need to expand bandwidth, is simple in structure, and realizes low nonlinear phase error, high efficiency and high power of the power amplifier.

The application discloses a phase-shift control method under full-bridge LLC high gain, selects two phase-shift frequency points in a high frequency band, which are a phase-shift control starting point frequency and a phase-shift control terminal point frequency respectively, simultaneously determines a maximum phase-shift period, obtains a linear phase-shift angle in the frequency range through linear function calculation, and thus can better reduce the high gain of the LLC circuit and does not affect the working state under heavy load. Meanwhile, the phase-shift angle of the starting point frequency is set to 0, seamless switching between a normal mode and a phase-shift mode can be realized, a wide input and wide output range of electric vehicle charging can be adapted, voltage ripple under light load and no load can be improved, and stability is improved.

The invention discloses a W-band GaAs on-chip integrated waveguide linear phase filtering network based on external phase equalization. Group delay planarization and size miniaturization are realized through an external equalization theory and an innovative resonant cavity layout and coupling mechanism. The core structure comprises a four-order SIW filter, a 3dB bridge, and two single-port reflection-type open-loop resonators. The output end of the four-order SIW filter is coupled with one port of the 3dB bridge, the two single-port reflective open-loop resonators are respectively connected with the other two ports of the 3dB bridge, and the last port of the 3dB bridge is used as the output port of the whole filter network.

The invention belongs to the technical field of radio frequency communication, and discloses a novel broadband linear phase filter and a design method thereof, and the novel broadband linear phase filter comprises a first port; a second port; the three first transmission lines are connected in series between the first port and the second port; wherein four connection points are formed between the first port and the adjacent first transmission line, among the three first transmission lines, and between the second port and the adjacent first transmission line; the four short-circuit branch lines are connected to the four connection points in a one-to-one correspondence manner; and one end of the inductive circuit module is connected to a connection point between the first port and the adjacent first transmission line, and the other end of the inductive circuit module is connected to a connection point between the second port and the adjacent first transmission line.

This invention provides a multi-octave broadband six-digit digitally controlled phase shifter with an all-through balun structure, belonging to the field of digitally controlled phase shifter technology. By combining phase shifting units with different timings and employing a switch-based linear phase shifting structure combined with a balun, this invention effectively achieves high-precision broadband phase shifting control from small steps to large angles. The use of negatively coupled inductors expands the operating bandwidth, optimizes phase linearity and stability, and the interleaved arrangement of large and small phase shifting units further reduces signal reflection and improves standing wave performance. By utilizing two sets of symmetrical single-pole double-throw switches to achieve fast and stable switching between the ground state and the phase-shifted state, the balance of the signal path and impedance matching are ensured, significantly improving the insertion loss and switching speed of the phase shifter. This not only meets the complex requirements of multi-octave broadband operation but also improves the reliability and integration of the system.

The invention discloses an extreme scene-oriented phase shifter locating and sizing method and system, and the method comprises the steps: constructing an annual hourly operation data set based on production simulation data; carrying out power flow out-of-limit judgment and N-1 safety verification on the operation data set, identifying a power flow out-of-limit scene and an unsafe scene in the operation data set, and constructing an extreme candidate scene set; selecting a representative extreme scene from the extreme candidate scene set by using a K-Medoids + + algorithm based on a weighted Euclidean distance; based on representative extreme scenes, under the conditions of various cost constraints, investment decision constraints and power grid operation constraints, a linearized phase shifter locating and sizing optimization model is constructed, a mixed integer programming solver is utilized to solve the phase shifter locating and sizing optimization model, and a locating and sizing result is obtained. The method can be suitable for locating and sizing of a plurality of phase shifters in various extreme scenes, and the solving process is fast and accurate.

The application discloses an audio signal processing method and device, electronic equipment and a readable storage medium, and belongs to the technical field of audio. The method comprises the following steps: acquiring a first audio signal; inputting the first audio signal into a target band-pass filter set for filtering processing to obtain a second audio signal, wherein the target band-pass filter set comprises N first band-pass filters, and the N first band-pass filters are related to each other; and performing signal processing on the second audio signal to obtain a third audio signal; wherein, in the case that the target band-pass filter set is a linear-phase FIR band-pass filter set, the first band-pass filter is an even-order filter; and in the case that the target band-pass filter set is a non-linear-phase IIR band-pass filter set, the first band-pass filter is designed according to the order of the first band-pass filter.

An embodiment of the present invention relates to a transmitting device (100) configured to transmit an OFDM signal (510) in a communication system (500). The OFDM signal (510) comprises N bit Each bit in the sequence of bits and N bit N spreading sequences are multiplied by the corresponding spreading sequences in the sequence symb To obtain N modulation symbols, bit It is obtained by spreading a sequence of N bits. bit Each spreading sequence in the sequence of N spreading sequences is a linear phase sequence with a constant rotation phase angle Φ. symb The modulation symbols are N symb The N Fourier coefficients are multiplied by the discrete Fourier transform precoder to obtain the N Fourier coefficients. Finally, the N Fourier coefficients are mapped onto the K OFDM subcarriers. symb An OFDM signal (510) comprising Fourier coefficients is transmitted. Furthermore, the present invention also relates to a corresponding method and computer program.

The invention belongs to the technical field of machining, and particularly relates to a method for accurately driving a target vibration mode of an ultrasonic broaching machine, which comprises the following steps of: S1, designing a band-pass filter, carrying out a frequency sweep test, determining an axial modal bandwidth and carrying out thermal drift compensation; s2, realizing a digital filter, and optimizing a transition zone by adopting a Kaiser Window (Kaiser Window); a filter coefficient is quantized into a 18-bit fixed-point number format, so that the calculation efficiency during hardware implementation is improved; the FPGA is used for accelerating the filter, and the FIR filter is designed and has a linear phase characteristic so as to ensure that the signal is not distorted due to the filtering process; a standby analog circuit design is designed to serve as a supplement of a digital filter, and more redundancy and stability are provided. The broach vibration mode can be accurately driven, the purity of axial vibration is remarkably improved, the radial vibration suppression ratio is increased, and the machining precision and stability of ultrasonic equipment are further improved.

The present application relates to the vehicle-road cloud integration cooperative communication and its safety transmission detection technical field, especially in vehicle-road cloud cooperative communication detection method and system, including the collection vehicle node sends baseband complex signal sequence and motion state vector, and combine the road space reflection map of cloud platform issue, according to motion state vector and road space reflection map extraction space propagation doppler frequency offset constraint condition.According to the constraint condition generates environment interference null feature dictionary matrix, the baseband complex signal sequence is executed orthogonal projection operation using environment interference null feature dictionary matrix, obtains the projection residual signal.From the residual signal, the isolated state phase sequence is extracted, and the projection residual energy ratio of the baseband complex signal sequence is calculated.Finally, according to the phase sequence and energy ratio, the abnormality judgment result is generated, the present application can effectively strip the deep overlap of nonlinear phase accumulation and environmental doppler shift, realize the accurate discrimination of hardware sudden failure and instantaneous environmental interference.

This invention discloses a TCN-based equalizer compensation method and system for in-vehicle audio systems, relating to the field of in-vehicle electronic equipment technology. The method includes: playing a test signal in an in-vehicle environment; acquiring distorted time-domain waveforms affected by the in-vehicle acoustic environment via a microphone and preprocessing them; inputting the processed waveform into a temporal convolutional network to extract multi-scale temporal features; predicting the first half of the coefficients of a linear-phase FIR filter after global average pooling and fully connected layer mapping; symmetrically flipping and splicing these first half coefficients to construct the complete linear-phase FIR filter coefficients, and performing DC gain normalization; finally, performing a one-dimensional convolution operation between the normalized FIR filter coefficients and the original audio signal to output a frequency-response compensated equalized audio signal. This invention achieves adaptive equalization compensation for in-vehicle audio systems, significantly improving sound quality and listening experience while maintaining linear phase characteristics.

This invention belongs to the field of antenna engineering technology, specifically providing a 1-bit encoded wide-bandwidth angle-scanning reflective array antenna to achieve high-speed, low-cost beam scanning with wide-bandwidth angle-scanning characteristics. This invention employs a wide-bandwidth horn feed and dipole antenna elements. The element structure uses a phase delay line with short-circuited terminations to control the phase, which not only provides wide-bandwidth characteristics but also minimizes inter-element coupling and mutual influence, suppressing resonance. Furthermore, the DC control structure is simple, significantly reducing the number of electronic control components and lowering the complexity of the electronic control method. In summary, this invention utilizes a stripline transmission line to achieve wide-bandwidth, low-loss linear phase shift and employs 1-bit encoding for high-speed, low-cost array phase electrical modulation to achieve wide-bandwidth angle-scanning, offering advantages such as simple structure and convenient electronic control.

The invention relates to the technical field of backscattering, and discloses a single-receiver WiFi backscattering communication method and system, and the method comprises the steps: enabling a label to receive an OFDM symbol from an environment WiFi signal, only applying a linear phase factor corresponding to a cyclic shift value related to the label to the middle part of a data load, reconstructing an OFDM symbol of the reflected signal based on the modulated data load middle part; the receiver extracts a modulated part from an OFDM symbol of the received reflected signal, performs frequency domain inverse shift compensation on each candidate cyclic shift value, and obtains a reconstructed data load based on the obtained compensated frequency spectrum; calculating a correlation score between the power spectrum of each reconstruction data load and a binary template predefined based on an empty subcarrier position; and decoding the cyclic shift value, and recovering the corresponding label data. According to the invention, high data throughput rate can be realized on the premise of not sacrificing OFDM compatibility.