41 results about "Transition band" patented technology

A broadband low-transmittance and high-absorption wave absorption and transmission integrated frequency selection surface comprises three wave absorption layers and two wave transmission layers which are sequentially stacked from top to bottom, and the three wave absorption layers are sequentially divided into an upper wave absorption layer, a middle wave absorption layer and a lower wave absorption layer from top to bottom; the two wave-transparent layers are sequentially divided into an upper wave-transparent layer and a lower wave-transparent layer from top to bottom; the multi-layer composite structure design is adopted, collaborative optimization of the wave absorbing performance and the wave transmitting performance is achieved by combining the two wave transmitting layers on the lower portion and the three wave absorbing layers on the upper portion, through organic combination of the upper layer structure and the lower layer structure, dual performance improvement of broadband wave absorbing and broadband wave transmitting is achieved, and a transition zone between a wave absorbing zone and a wave transmitting zone is greatly reduced.

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 provides a filtering windowing method, device, equipment and medium in a uRLLC scene, and the method comprises the steps: extracting an orthogonal frequency division multiplexing symbol from time domain data; expanding each symbol to obtain an expanded sequence of each symbol; windowing the extended sequence of each symbol to obtain a windowing sequence of each symbol; and obtaining an output sequence after filtering processing according to the windowing sequence of each symbol. According to the method provided by the invention, the windowing sequence is obtained by windowing after the symbol is expanded, and the filtered output sequence is obtained according to the windowing sequence, so that the real-time requirement can be ensured, and the signal can have sharper attenuation in transition.

The invention relates to the technical field of radar detection and application thereof, and provides a data processing method for ground penetrating radar data, which comprises the following steps: firstly, carrying out preprocessing and gain recovery on original radar data, then carrying out mixed denoising by adopting empirical mode decomposition and Wiener filtering, screening and reconstructing effective signals by utilizing cross correlation coefficients, and finally, carrying out data processing on the effective signals. The method comprises the following steps: firstly, constructing a filter in a frequency wave number domain to remove random noise and low-frequency interference, then constructing a fan-shaped filter in the frequency wave number domain, introducing transition band processing to suppress linear coherent interference, then carrying out wave velocity estimation based on an image entropy minimization criterion to obtain an optimal imaging wave velocity, and finally executing Stolt migration imaging by using the optimal wave velocity and outputting a result. According to the method, edge details of effective signals are effectively reserved through multi-scale decomposition, the problem of imaging defocusing is solved through self-adaptive wave velocity search, and the signal-to-noise ratio, the resolution ratio and the focusing precision of ground penetrating radar data in a complex and strong-interference environment are remarkably improved.

The invention discloses a cascade frequency selective surface with a steep transition band and a wide passband. The cascade frequency selective surface sequentially comprises a frequency selective surface with a steep sideband, a honeycomb core layer and a frequency selective surface with a wide passband from top to bottom along a Z-axis direction, the frequency selective surface with the steep sideband is used for providing a frequency response characteristic of rapid roll-off at the edge of a passband to form a steep transition band; the frequency selective surface with the wide passband is used for providing a broadband wave-transparent characteristic and a broadband stop-band suppression characteristic; the honeycomb core layer is used for cascading a frequency selective surface with a steep sideband and a frequency selective surface with a wide passband; and electromagnetic coupling between the upper and lower layers of frequency selection surfaces is reduced, so that the frequency selection surface with a steep sideband and the frequency selection surface with a wide passband maintain relatively independent resonance characteristics. According to the invention, the square annular patch with central symmetry is used, and the four branches are added, so that the symmetry enables the angle to be stable, and the processing complexity is simplified.

The application discloses a kind of facet angle parameter automatic calculation and process parameter mapping method and system, it is related to digital parameter processing technical field;Method includes: the angle difference of each facet junction of lens is acquired in advance;For each facet junction, in the minimum transition bandwidth reference data acquired in advance, according to the corresponding angle difference, form transition bandwidth lower limit list;Based on the optical sensitivity distribution data acquired in advance, form transition bandwidth upper limit list;Based on transition bandwidth lower limit list and transition bandwidth upper limit list, conflict determination and solution are carried out, and form final transition bandwidth list;Based on facet angle matrix and final transition bandwidth list, transition band geometry is generated for each facet junction, and new lens surface model is obtained;The application can consider the dual needs of facet angle keeping and step elimination, so that transition bandwidth adapts to the optical and processing requirements of different regions.

The application discloses a resonator and a compact ultra-narrow-band high-temperature superconducting filter, which adopts SISO spiral structure and interdigital structure to form a dual composite left-right hand resonator in parallel, wherein the interdigital structure forms an open end of the resonator, the SISO spiral structure forms a closed end of the resonator, and the interdigital structure is composed of a plurality of mutually parallel interdigital branches; the interdigital structure is used for introducing a left-hand capacitor and increasing an equivalent capacitance of the resonator; a first end of the interdigital structure is directly connected with a microstrip line and spirals in a clockwise direction, spirals out in a counterclockwise direction along the microstrip line at a rotation center, bypasses the interdigital structure, is connected to a second end of the interdigital structure to form the SISO spiral structure; and the overall filter size can be greatly reduced, the insertion loss in a passband of the filter, the out-of-band suppression capability, the roll-off coefficient of a transition band are greatly improved, and the selectivity of the filter is enhanced.

The invention relates to the technical field of band elimination filters, and discloses a V-band H-plane rectangular waveguide TE20 mode band elimination filter which comprises a body and a cover plate installed on the body. A main waveguide cavity is arranged on the body, a plurality of TE20 mode rectangular resonant cavities are symmetrically distributed on two sides of the main waveguide cavity, and each TE20 mode rectangular resonant cavity is communicated with the main waveguide cavity through an H-surface capacitance coupling window; a tuning screw is arranged on the cover plate, the tuning screw comprises a threaded part and a light pillar part, the light pillar part extends into the TE20 mode rectangular resonant cavity, and the threaded part is matched and fixed with a threaded hole in the cover plate; the band elimination filter solves the problems that an existing band elimination filter is wide in transition band and large in loss.

This invention addresses the problem that the direct zeroing method used in existing satellite navigation signal processing frequency domain FFT notch filtering easily leads to power loss near interference frequencies, affecting signal integrity. It proposes a narrowband interference suppression system and method for BeiDou navigation. The narrowband interference suppression system includes a BeiDou RF front-end module, a high-speed ADC sampling module, a digital down-conversion (DDC) module, a signal distributor and buffer module, an interference detection and parameter estimation unit, an interference suppression execution unit, a baseband correlation and demodulation module, and a navigation and positioning result output module. A cascaded array of IIR notch filters is constructed using a cascaded array module. A steep transition band is achieved through small-order serial units, and the stopband width of the notch filters can be flexibly adjusted via a convergence factor. This enables precise suppression of extremely narrow stopband interference at different bandwidths, filtering out signals only at interference frequencies, effectively avoiding impact on surrounding useful BeiDou signals and preventing spectrum leakage.

This application relates to the field of image processing technology, and in particular to a machine vision-based method for detecting the filling quality of sound-absorbing materials in sound barriers. The method includes: acquiring a sequence of synchronized infrared and visible light video frames, performing pixel-level registration, and then stitching them together to form multi-channel input features; constructing a detection network containing an improved octave convolution module to decompose the multi-channel input features into three branches: high-frequency, mid-frequency, and low-frequency; generating an offset field and performing deformable convolution on the mid-frequency branch; averaging the variance of each channel in the feature map along the channel dimension, adding a minimum constant, and taking the square root as a temperature coefficient; performing cross-frequency fusion through a cross-attention mechanism; and extracting the low-frequency feature map as a spatial prior weight matrix when a defect region exists in the current frame, which is then fed back to the next frame after inter-frame motion compensation. This application can introduce mid-frequency transition band information and combine the differences in local spatial distribution of dual modalities to adjust the convolution sampling position, reducing boundary jitter and missed detections in video stream detection.

The invention discloses an interpolation filter design method based on fuel measurement signal multi-phase decomposition, and belongs to the technical field of filter digital signal processing. According to the method, the cut-off frequency and transition band characteristics of an interpolation filter are optimized through the multi-sampling-rate conversion theory and the multi-phase decomposition technology, and filtering parameters are dynamically adjusted in combination with an adaptive algorithm; the high-precision reconstruction of a fuel measurement signal is realized; the core is that a rear digital low-pass filter is designed, a frequency spectrum compression and expansion technology is used for inhibiting an aliasing effect, and calculation efficiency is improved through a multiphase decomposition structure; the method is especially suitable for an aviation fuel measurement system, can balance data redundancy and signal fidelity under different sampling rates, and significantly improves the measurement precision and the system stability.

The invention provides a CT (Computed Tomography) key frame selection method based on complex phase constellation coding. The CT key frame selection method comprises the following steps: step 1, slice complex phase symbolization: slices are changed into complex phase symbols capable of being rechecked; step 2, performing W-CCPS segmentation on an amplitude-coupled circular phase change point codebook, and changing a selected frame into proved continuous coverage; step 3, irreplaceable pilot frequency selection and transition zone closed-loop frame supplementation are carried out; and step 4, generating CPDE through variable-point driving evidence, and outputting an auditing evidence packet. The method has the advantages that coverage can be verified and closed-loop, cross-protocol robustness and interpretability are achieved, excessive segmentation driven by noise is avoided, the risk of missed reading of a transition belt is reduced, and expandability is achieved.

The invention relates to the technical field of radar detection, and discloses a design method and device of a radar MTI filter and a storage medium, and the method comprises the steps: dividing the whole response interval of the MTI filter into a pass band and a transition band according to the response of a system in a static environment, and discretizing the pass band and the transition band; setting the order N of the MTI filter, and taking the minimum passband flatness as a cost function; derivative constraint is applied to the response of the direct current position of the MTI filter, and 2-norm constraint is applied to the response of the transition band of the MTI filter; and solving the cost function, and taking the optimal solution of the cost function as the coefficient of the MTI filter. The MTI filter can have a deeper and wider notch near the zero Doppler frequency, and the width of the transition band is controllable.

This invention discloses an active frequency selective surface with a steep passband edge drop and polarization stability, belonging to the field of microwave device technology. The structure comprises periodically arranged unit cells, each employing a three-layer symmetrical configuration, including a top and bottom layer of identical square annular aperture metal patch, a middle layer of cross-shaped mesh metal patch, and an interlayer dielectric substrate. Multiple varactor diodes are symmetrically integrated within the square annular aperture. By continuously adjusting their reverse bias voltage, the junction capacitance is changed, thereby achieving continuous and smooth tuning of the center resonant frequency within the range of 7.75 GHz to 11.2 GHz. This invention achieves a rapid passband edge drop over a wide tuning range through the coordinated resonance of a multi-layered symmetrical structure. The transition band width from -3 dB to -10 dB does not exceed 0.6 GHz, while also exhibiting excellent polarization independence and angular stability, making it suitable for high-performance applications requiring dynamic frequency selection, such as microwave communication and radar detection.

The application discloses a kind of broadband narrow transition zone and frequency selective surface with good wide-angle stability, belong to electromagnetic surface technical field.The frequency selective surface described in the application is composed of four layers structure, butterfly-shaped metal patch is printed on the 1st, 3rd layer dielectric plate, metal column connects butterfly-shaped metal patch up and down;Metal mesh is printed on the 2nd layer dielectric plate on single side;Cross-shaped patch is printed on the back side of butterfly-shaped metal patch, composite square patch is printed on the top layer and bottom layer dielectric plate respectively as wide-angle matching layer.The application designs the passband of frequency selective surface by designing the operating frequency band of butterfly-shaped dipole antenna, and adjusts the wide-angle stability by introducing wide-angle matching layer and capacitive patch.The application can realize stable passband transmission performance under different polarizations and incident angles within 2.3-4GHz, and the passband loss is within 1dB.The transition zone bandwidth of transistion is relatively narrow, which is 6.7%, the stopband frequency band is 0.5-2.15GHz, and the stopband suppression is greater than 10dB, with excellent reflection performance.

A label creation device includes processing circuitry configured to: acquire training data in which a feature to be used to create a diagnostic model used in degradation diagnosis on a target apparatus as a degradation diagnosis subject is associated with external factor data related to an operating environment; classify a range of value of the external factor data into a constant band that is a range of value of the external factor data in which a relationship with the corresponding feature is estimated to be constant, and a transition band that is a range of value of the external factor data in which the relationship changes frequently; and assign an external factor label indicating that a relationship is constant, assign an external factor label indicating that the relationship changes frequently, with respect to the axis of the external factor data, and create external factor label data.

The invention relates to a flat passband filter circuit based on high-order cascading. The circuit comprises a high-order high-pass filtering module and a high-order low-pass filtering module which are cascaded in sequence to form a one-way processing path from a signal input end to a signal output end. Wherein the orders of the high-pass module and the low-pass module are not less than 6, and the cut-off frequencies of the high-pass module and the low-pass module are respectively set as the lower limit and the upper limit of a passband, so that a flat passband range is cooperatively defined. A Sallen-Key Butterworth structure is preferably adopted, and resistance-capacitance parameters of all levels are optimized, so that the excellent performance that the amplitude fluctuation in a passband is less than + / -0.5 dB and the roll-off rate of a transition band is greater than 80dB / octave is realized while high selectivity is ensured. The filter circuit provided by the invention effectively solves the contradiction between uneven passband and smooth transition band of the traditional band-pass filter, and is suitable for a precision electronic system with high requirements on signal fidelity and adjacent channel suppression.

The application discloses a method, device and equipment for designing a channel filter and a computer storage medium, and relates to the technical field of wireless communication. The method comprises the following steps: acquiring a signal bandwidth, a baseband sampling rate, a frequency of adjacent channel interference, a noise power spectral density of adjacent channel interference and a noise power spectral density of a signal; calculating a normalized passband cutoff frequency, a normalized stopband cutoff frequency and a stopband attenuation according to the acquired parameters; determining a channel filter coefficient according to the normalized passband cutoff frequency, the normalized stopband cutoff frequency and the stopband attenuation, and obtaining a channel filter corresponding to the channel filter coefficient; inserting a preset value into the channel filter coefficient to obtain a target channel filter coefficient, updating the channel filter, and obtaining a target channel filter. The embodiment of the application realizes the design of a steep transition band channel filter while reducing the structural complexity.

The invention relates to a night scene image enhancement processing method and device and electronic equipment. According to the embodiment provided by the invention, the adaptive transition region is determined based on the attribute difference of the sensing pixel blocks, and compared with a rigid mode of firstly dividing two types of regions and then forcibly adding a transition zone in the traditional technology, the obtained sensing pixel blocks can have the characteristics of high in-block visual consistency and large inter-block difference; a traditional fixed color protection area concept is replaced, a protection / enhancement boundary is enabled to adaptively change along with content, a fixed threshold does not need to be manually preset, the problem that traditional static threshold division is disjointed with an actual scene is thoroughly solved, the division accuracy is effectively improved compared with a traditional method, and the method is suitable for large-scale popularization and application. The problem of color block breakage caused by sudden change of color / brightness at the boundary of the transition region in the image enhancement processing process is solved.

The invention belongs to the technical field of multi-phase filters, and particularly relates to a linear combination window function generation method, program and device for a GFB-OFDM waveform multi-phase filter and a storage medium. Linear weighting is carried out on the raised cosine window function and the Hanning window function through the weighting coefficient, the advantages that the low sidelobe attenuation of the raised cosine window is fast and the main lobe width of the Hanning window is appropriate are comprehensively utilized, the sidelobe level is reduced, meanwhile, the main lobe width is in an appropriate range, and the accuracy of the method is improved. Therefore, a good balance is obtained between suppression of spectrum leakage and guarantee of frequency resolution, and the overall performance of signal processing is improved. By adjusting the weight ratio of the raised cosine window to the Hanning window, the main lobe width and the side lobe attenuation can be flexibly balanced, and the narrower main lobe width or the steeper transition zone can be obtained for different application scenes.

The invention provides a high-selectivity one-to-four filtering power divider based on stub loaded resonators and T-shaped E-plane stepped waveguides, which relates to the technical field of filtering power dividers and comprises a third-order stub filter and a four-way power divider. An input signal firstly passes through the third-order stub filter and then is divided into four paths of output signals through the four-path power divider. Through the synergistic effect of the stub loaded resonators and the E-plane stepped waveguides, six transmission zeros can be generated on the two sides of a Ku wave band pass band, the steepness of the edge of the pass band reaches-40 dB or below, pass band and stop band signals are effectively distinguished, the frequency selectivity is improved, and the problems that in the prior art, the pass band transition bandwidth is large, and interference suppression is poor are solved.

Comprehensive: a training data acquisition unit (11) that acquires training data in which a feature and data relating to an external factor are associated with each other; a partitioning unit (12) for a region of the external factor that classifies a range of values ​​of the data relating to the external factor in the axial direction of the data relating to the external factor into a constant band and a transition band;and an external factor indicator data generation unit (13) which, with respect to the axis of the data relating to the external factor, generates external factor indicator data in which value ranges of the external data are associated with external factor indicators by assigning an external factor indicator, indicating that the range is a range in which the relationship between the data relating to the external factor in the range and the corresponding feature is constant, to the value range of data relating to the external factor which is classified as the constant band, and an external factor indicator, indicating that the range is a range in which the relationship between the data relating to the external factor in the range and the corresponding feature changes frequently, to the value range of data relating to the external factor which is classified as the transition band.

This invention relates to the field of noise reduction technology, specifically to an AI-based intelligent noise reduction method for laser-modulated speech, comprising the following steps: Analog-to-digital conversion: A high-speed, high-precision analog-to-digital conversion module is used to convert analog data into digital signals, and noise reduction is performed only on human voices according to the usage scenario; Digital filtering: Bandpass filtering technology is used to filter out all out-of-band signals; AI intelligent processing: Spectral subtraction is used to eliminate background noise. By constructing a collaborative processing link of "high-precision analog-to-digital / digital-to-analog conversion—64th-order narrow transition band FIR filtering—dynamic spectral subtraction based on AI model library", for slow-changing and stable specific background noise such as mechanical vibration thermal noise of the laser itself and ambient optical path scattering interference, a 10-millisecond non-overlapping time slice and a joint decision mechanism of three parameters (mean, variance, and entropy) of Mel frequency cepstral coefficients are used to achieve accurate dynamic tracking of noise targets and adaptive stripping of speech signals.

The invention relates to the technical field of signal generation, and discloses a signal generation system and method.In a frequency mixing and phase locking module, the first input end of a frequency mixing unit is connected with the output end of a dot frequency selection unit, the second input end of the frequency mixing unit is connected with the output end of a signal adjustment unit, and the output end of the frequency mixing unit is connected with the input end of a sideband selection unit; the first input end of the signal adjusting unit is connected with the output end of the sideband selection unit, and the second input end is connected with the output end of the frequency synthesis module; the input end of the dot frequency selection unit is connected with the output end of the dot frequency generation module; the input end of the frequency synthesis module is connected with the output end of the dot frequency generation module. Therefore, the frequency band coverage of a single dot frequency signal is expanded through a sideband switching mode, the number of required dot frequency signals is reduced, the number of required filters is reduced, the hardware complexity of a system is reduced, meanwhile, the frequency interval of the dot frequency signals can be expanded, the transition band requirement of the filters is reduced, and the signal-to-noise ratio of the system is improved.

The embodiment of the invention discloses a digital filter, a construction method, electronic equipment and a computer readable storage medium, and belongs to the technical field of communication. The digital filter comprises a preprocessing unit, a shift selection unit, a shift complement unit and a symbolic operation unit, wherein the preprocessing unit is designed based on coefficient digits; the shift selection unit is designed based on the number of coefficient bits, the filter order, and the distributable coefficient bit width. The embodiment of the invention at least solves the technical problem that the hardware complexity is high when a high-order narrow transition band digital filter is realized in the prior art.

The invention belongs to the technical field of electromagnetic stealth, and discloses a frequency selective surface unit and a reconfigurable frequency selective surface. The frequency selection surface unit adopts a cascade unit structure of four metal layers and three dielectric layers, and a PIN diode, a feed connecting line, a square patch, a double-square-ring patch shaped like a Chinese character'hui ', a single-square-ring patch and the like are combined to form a filtering structure with good performance. According to the reconfigurable frequency selective surface, lower passband insertion loss, wider passband, better incident angle stability, narrower transition band, better out-of-band rejection and good polarization stability are achieved, and the problems that an existing reconfigurable frequency selective surface is insufficient in passband bandwidth, poor in out-of-band rejection and the like are solved. According to the reconfigurable frequency selective surface, the PIN diodes and the patch structures on all the units are connected through the metal feed connecting lines, so that after the array structure is formed, all the units can be fed only by feeding a certain unit, the design of an extra feed network layer is avoided, and the unit structure is simplified.

The application relates to the technical field of grating signal processing, and discloses a micron-level position adjustment and control system based on a grating, which comprises a signal acquisition and analysis module, a jitter identification module, an intelligent optimization module and a spectrum reconstruction module.The signal acquisition and analysis module is used for acquiring original electric signals of the grating and performing frequency domain conversion processing on the original electric signals to generate a frequency domain spectrum; the jitter identification module is used for identifying interference frequency components in the frequency domain spectrum based on a preset characteristic frequency range of a displacement signal; the intelligent optimization module is used for constructing an initial interference set and optimizing spectrum reconstruction parameters through a genetic algorithm; the spectrum reconstruction module is used for performing amplitude suppression and phase compensation on the interference frequency according to an optimization result and performing transition band smoothing processing; and the signal reconstruction module is used for restoring the frequency domain spectrum to a time domain signal, correcting phase distortion and outputting a stable displacement measurement result.The application realizes adaptive identification and reconstruction suppression of interference frequencies in a grating signal, and improves the precision and stability of displacement measurement.

The present invention relates to the technical field of communication circuits, and specifically to a broadband hybrid high-roll-off low-pass filter unit, a broadband hybrid high-roll-off low-pass filter circuit, and a related device. The filter unit comprises an input end, an output end, and a primary signal path and a secondary signal path that are arranged in parallel between the input end and the output end; the primary signal path is provided with an LC low-pass filter; the secondary signal path is provided with an acoustic resonator and an LC filter that are connected in series; moreover, after signals of the same target frequency respectively pass through the primary signal path and the secondary signal path, the phase difference of the signals is 180 degrees, and the target frequency is located in a transition band of the LC low-pass filter. In this way, when the unit is used for filtering, the unit not only has the advantage of large broadband of the LC low-pass filter, but also can form a plurality of transmission zero points because the phase difference of the signals of the target frequency is 180 degrees and vector cancellation is realized after the signals respectively pass through the primary signal path and the secondary signal path, thereby achieving the purpose of improving the roll-off of the transition band, and satisfying the requirements for a large bandwidth and high roll-off.

The application discloses a reconfigurable transition Butterworth-elliptic filter based on transistor switches, which comprises a transition Butterworth-elliptic filter including a plurality of capacitors and inductors, the capacitors and the inductors are connected in a ladder shape, wherein the inductors are connected in series in a signal path, the capacitors are connected in parallel to the ground, and one capacitor is connected in parallel to both sides of the inductor at the end of the circuit; the capacitors connected in parallel to the ground in the transition Butterworth-elliptic filter are respectively provided with n first transistor switch-capacitor networks in parallel, and the capacitors connected in parallel to both sides of the inductor are provided with n second transistor switch-capacitor networks in parallel. The circuit structure of the transition Butterworth-elliptic filter is adopted, the frequency response has the characteristics of flatness in a passband and rapid roll-off in a transition band, and the values of the inductors and the capacitors are relatively small, thereby saving the chip area. The switch-capacitor network is introduced, the order is adjustable, the relatively small chip area and the relatively fast switching speed are realized.