95 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 present invention discloses a broadband high-steepness filter based on the embedding of a piezoelectric acoustic resonator and an LC passive circuit, which includes a ladder-type filtering network and an LC resonance network. The ladder-type filtering network and the LC resonance network are connected in series in sequence, or the ladder-type filtering network and the LC resonance network are connected in series at intervals in sequence. The ladder-type filtering network includes a filtering series main path and a plurality of filtering parallel branches. The first end of the filtering series main path serves as the input end, and both ends of the filtering parallel branches are respectively connected to the ground wire and the series main path. At least one series hybrid resonance unit is arranged on the filtering series main path, and the series hybrid resonance unit is used to form poles in the passband to expand the passband bandwidth. At least one acoustic resonator or parallel hybrid resonance unit is arranged on the filtering parallel branch. This filter can achieve a relatively high bandwidth, a relatively high out-of-band rejection, and a relatively narrow transition band.

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.

A frequency selective unit, a frequency selective surface, and an antenna base station. The frequency selective unit comprises a metal reflector plate and at least two conductive material pattern layers, wherein through holes are provided in the metal reflector plate, the at least two conductive material pattern layers run through the through holes, and there is a gap between the conductive material pattern layers and the metal reflector plate; and at least one conductive material pattern layer comprises a first transmission mode, and at least the other conductive material pattern layer comprises a second transmission mode, and in a transition band, electromagnetic waves in the two transmission modes have opposite phases and cancel each other, such that the electromagnetic waves cannot be transmitted through the frequency selective unit; moreover, an electromagnetic wave transmission zero can be generated in the transition band, and a sharp roll-off is formed at an out-of-band edge of a second band, thereby realizing high-frequency selectivity. The conductive material pattern layers are not parallel to the metal reflector plate, the transmission direction of the electromagnetic waves is parallel to the surfaces of the conductive material pattern layers, and it is not necessary to provide a metallized via hole between the at least two conductive material pattern layers to perform electrical connection, thereby simplifying the manufacturing process and processing difficulty of the frequency selective unit.

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.

Methods, systems, and devices for wireless communications are described in which a repeater may provide assistance information and configuration requests for full-duplex communications. The assistance information may include information about filtering capabilities of the repeater, such as sub-bands that can be filtered to avoid cross-link interference (CLI) or self-interference (SI), a width of a pass-band or transition band, a level of rejection associated with repeater filters, and the like. The assistance information may also indicate an amount of guard-band needed between uplink and downlink sub-bands, supported sub-bands, supported transmit power or amplification levels, phase continuity capabilities, transition times between full-duplex and non-full-duplex symbols, or any combinations thereof. Additionally, or alternatively, the assistance information may indicate support for multiplexing between mobile termination (MT) and forward (FWD) units at the repeater, and CLI measurements associated with MT and FWD unit multiplexing may be provided.

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 relates to instrumentation amplifiers and biosignal acquisition methods, specifically to a capacitively coupled instrumentation amplifier and biosignal acquisition method. It solves the technical problems of poor accuracy and integrity of biosignals acquired by existing instrumentation amplifiers, as well as their large area. This invention employs an input impedance enhancement circuit to increase the input impedance, resulting in more complete biosignals. It also uses a transimpedance matching enhancement circuit to increase the matching degree between the output signal of the feedback loop and the differential output signal. Simultaneously, by reducing the feedback capacitor to increase the closed-loop gain and lower the requirement for the input capacitor, it not only reduces the area but also increases the input impedance, improving the accuracy and integrity of the acquired biosignals. The second-order DC electrode offset cancellation circuit uses a second-order low-pass filter to narrow the transition band, more effectively separating the DC electrode offset signal from the biosignal, eliminating the DC electrode offset problem during biosignal acquisition, and making the acquired biosignals more accurate.

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.

The invention discloses a signal transceiving processing method and system based on a deep neural network, and relates to the technical field of wireless communication. Signals of different modulation systems can be generated, and the bit error rate performance is remarkably improved through receiving and transmitting joint optimization; on the basis of meeting SEM constraints, transition band and stop band resources of SEM are fully utilized, and remarkable SE gain is realized; in a frequency selective fading channel, compared with the conventional modulation scheme, the maximum signal-to-noise ratio gain of 20dB is obtained; an introduced data detector based on large kernel attention not only effectively reduces large-span interference information, but also greatly reduces calculation complexity; the method does not depend on a channel prior model, and channel characteristics are implicitly embedded through data driving, so that the method can be switched as required in diversified wireless environments, and stable performance is kept.

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.

An acoustic filter assembly for operating at a target band including multiple spaced sub-target bands. The filter assembly includes a first filter that passes a first band and a second filter that passes a second band. The first filter and the second filter have a transition band between the first band and the second band that is wider than the spacing between the sub-target bands. An interface receives a control signal that controls the transition band to be shifted between a first position and a second position, such that an upper part of a lower sub-target band is covered by the first band in the first position, and a lower part of an upper sub-target band is covered by the second band in the second position.

The invention discloses an anti-symmetric filter design method based on an anti-auto-inverse matrix theory, and belongs to the technical field of digital signal processing. According to the method, a design problem of an antisymmetric filter is modeled into an optimization problem of an impulse response vector h, and an inverse self-inverse constraint h =-Jh (J is an inverse unit matrix) is applied, so that an optimization target minize | A -d | is constructed. An iterative solution technology of a generalized coupling Sylster transpose matrix equation is adopted, and through parameter initialization, residual matrix updating, step length dynamic adjustment and anti-auto-back projection operation, it is ensured that a filter coefficient strictly meets antisymmetry. Furthermore, the calculation complexity is reduced by using block calculation, fast multiplication and a precondition technology, and the frequency domain performance is optimized in combination with a weighted least square method and a Lagrange multiplier method. According to the filter designed by the invention, the strict linear phase characteristic is maintained, meanwhile, the stop-band attenuation can reach more than 50dB, the gradient of a transition band is improved by 30%, and the group delay fluctuation is controlled within 0.1 sampling point, so that the filter is suitable for medical image and radar signal processing and high-fidelity audio systems, and has the characteristics of high calculation efficiency and excellent performance.

This application discloses an improved iterative design method for multi-channel cosine-modulated filter banks. The aim is to improve the performance of the prototype filter in terms of aliasing error control and system response by introducing constraints on the amplitude-frequency characteristics of the passband and transition band of the prototype filter into the optimization objective. Compared with traditional iterative design methods, the method proposed in this application shows superior performance in these performance indicators. Furthermore, based on the closed-form expression of the objective function given in this application, an iterative solution method can be used to obtain the optimization results, further effectively reducing the computational complexity and implementation difficulty of the proposed method.

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 present invention discloses a hybrid filter integrating a piezoelectric acoustic wave resonator with a large bandwidth and a high-steepness sideband and a passive microwave device, characterized in that it includes a low-pass part, and the low-pass part includes a low-pass series trunk and a plurality of low-pass parallel branches; wherein, the low-pass series trunk includes a plurality of LC resonance units connected in series in sequence; the low-pass parallel branches are connected between the low-pass series trunk and the ground wire, and at least one LC resonance unit is spaced between adjacent two low-pass parallel branches, and the low-pass parallel branch includes a low-pass branch capacitive element, or a plurality of series-connected low-pass branch capacitive elements, and part or all of the low-pass branch capacitive elements adopt piezoelectric acoustic wave resonators. This hybrid filter has a large bandwidth and meets the requirements of a narrow transition band and high adjacent-band rejection.

An acoustic filter assembly for operating at a first band adjacent to a second band without a spacing between the first band and the second band is presented, including a band-pass filter configured have a transition band between the passband and a stopband; and an interface configured to receive a control signal that controls a width of the pass band such that the transition band is shifted in frequency, the control signal adjusting a location of the transition band between a first position and a second position, one end of the transition band near to the stopband being aligned with a boundary between the first band and the second band in the first position, the other end of the transition band near to the pass band being aligned with the boundary between the first band and the second band in the second position.

The invention relates to a crack arrest design method and a crack arrest structure for a bonding area of a pressure-bearing wall plate structure, and the crack arrest design method comprises the following steps: S1, determining a buckling deformation profile of the pressure-bearing wall plate structure when bearing a compression load, determining the position of the minimum deformation in the length direction of a stringer, and determining a crack arrest area according to the position; s2, a crack arrest notch is formed in the edge of the outer side of the cap bottom plate in the crack arrest area, the crack arrest notch gradually becomes smaller from the outer side to the inner side, and the edge is in smooth transition; s3, a gasket is made of the same material as the cap bottom plate, the gasket is matched with the crack-arrest notch in shape and consistent with the crack-arrest notch in thickness, the gasket is arranged in the crack-arrest notch and fixedly bonded with the wall plate, and the edge of the gasket is not fixedly connected with the edge of the crack-arrest notch; and S4, a laying layer is arranged on the cap bottom plate in the crack arrest area to serve as a transition belt plate, and the transition belt plate completely covers the crack arrest notch and is bonded and fixed to the cap bottom plate. The crack arrest structure is obtained through a crack arrest design method.

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.

A frequency selection unit, a frequency selection surface and an antenna base station wherein the frequency selection unit comprises a metal reflecting plate and at least two groups of conductive material pattern layers. The metal reflecting plate is provided with through holes, at least two groups of conductive material pattern layers are arranged in the through holes in a penetrating mode, and gaps are formed between the conductive material pattern layers and the metal reflecting plate. At least one group of conductive material pattern layer comprises a first transmission mode, at least another group of conductive material pattern layer comprises a second transmission mode, and electromagnetic wave phases in the two transmission modes are opposite and counteract each other in a transition band frequency band, so that the electromagnetic waves cannot be transmitted through the frequency selection unit; and meanwhile, an electromagnetic wave transmission zero point can be generated in the transition band frequency band, and a steep drop is formed at the out-of-band edge of the second frequency band, so that high-frequency selectivity is realized. The conductive material pattern layers are not parallel to the metal reflecting plate, the transmission direction of electromagnetic waves is parallel to the surfaces of the conductive material pattern layers, and at least two groups of conductive material pattern layers are electrically connected without metallized via holes, so that the manufacturing process and the processing difficulty of the frequency selection unit can be simplified.

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.

The invention discloses a low-insertion-loss low-frequency wave-transparent high-frequency wave-absorbing frequency selection absorber which is arranged in a manner of a plurality of periodic P arrays and comprises an upper loss layer and a lower transmission layer which are arranged from top to bottom, the upper loss layer comprises a first loss layer, a second loss layer and a third loss layer which are sequentially arranged from top to bottom; the lower transmission layer comprises a first frequency selection surface located at the upper part and a second frequency selection surface located at the lower part, and a gap is formed between the first frequency selection surface and the second frequency selection surface, is filled with a medium and is used for supporting the first frequency selection surface and the second frequency selection surface; the low-pass wave absorber solves the problems that an existing low-pass wave absorber is high in transmission frequency band insertion loss, wide in transmission and wave absorbing frequency band transition band, not wide enough in wave absorbing frequency band and the like, high-frequency selection and broadband wave transmission and wave absorbing characteristics can be achieved, and the low-pass wave absorber is simple in structure and easy to machine.

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.