1079 results about "Frequency selection" patented technology

A tracking and adaptive compensation method for power fluctuation of a pulse load of a ship is provided. The method includes: based on a microgrid topology model of the ship, a pulse load model of the pulse load, and an interharmonic power and pulse parameter relationship model, performing power fluctuation tracking, frequency selection and a power spectrum analysis to obtain filtering parameters of a low-pass filter and filtering parameters of a band-pass filter; performing waveform adaptation to eliminate a phase delay caused by the low-pass filter and the band-pass filter, and obtaining a control command for a power compensation strategy; and generating, by a power loop, a pulse width modulation (PWM) signal to control a switching tube in a bidirectional direct current (DC) / DC converter of each of an energy storage battery pack and a supercapacitor of a hybrid energy storage system.

The invention overcomes the constraints imposed by conventional wireless communication standards by introducing a physical-layer optimized architecture that decouples transmission control from any single protocol. Rather than being confined by the predefined behaviors of LTE, 5G NR, Wi-Fi, or NB-IoT, the system implements a unified control system that dynamically manages radio parameters—such as modulation, coding, and power—based on real-time link quality and network context. This cross-standard, multimode capability effectively supersedes traditional standard-driven implementations, enabling adaptive, low-latency, and spectrum-efficient communication in complex heterogeneous environments.The system dynamically controls radio access network (RAN) and physical layer parameters, including carrier aggregation, dynamic spectrum allocation, modulation and coding scheme (MCS) adaptation, beamforming configuration, channel coding, transmit power control, and frequency selection. The system architecture includes multi-mode base stations, relay nodes, and edge access points that support inter-RAT handover, fast radio link recovery, and seamless mobility across diverse wireless technologies.

The invention relates to the technical field of power system management, in particular to a Beidou-based power grid emergency wireless communication monitoring system, which comprises a Beidou No.3 communication subsystem for realizing power business data encryption transmission, positioning and long message processing through a Beidou data transmission terminal and a handheld terminal; the short-wave communication subsystem establishes a communication link by using an autonomous frequency selection technology when no public network coverage exists; the Tiantong satellite communication subsystem provides voice and real-time data transmission service by means of a Tiantong satellite terminal; the converged communication control module dynamically switches communication links according to the channel quality, the service priority and the energy consumption index; the protocol conversion module realizes mutual conversion between electric power meter reading and a Beidou protocol; and the unmanned aerial vehicle relay extension module constructs an air relay link with the ground relay base station through the unmanned aerial vehicle group to extend Beidou signal coverage. According to the invention, efficient, reliable and wide power grid emergency communication is realized, and remarkable creativity and practicability are achieved.

A system for material detection and identification including: an RF transmitter configured for transmitting into an environment an RF signal at a first resonance frequency for a target material, wherein the first resonance frequency is obtained from a material database associating each of a plurality of materials with one or more corresponding resonance frequencies; an RF receiver configured for receiving a resultant response signal from the environment; and a processor configured for: analyzing the resultant response signal for resonance characteristics that indicate a presence of the target material, wherein analyzing includes, if the resonance characteristics are detected and no other material in the material database shares similar resonance characteristics for the first resonance frequency, reporting to a user that the target material has been identified.

The invention discloses a medical image fuzzy boundary segmentation system and method based on COD frequency domain guidance. In order to solve the problem of boundary fuzzy segmentation of a medical image under a complex background, frequency domain feature processing and an improved camouflage target detection (COD) algorithm are innovatively combined, and a progressive boundary optimization segmentation framework FEA-Net is designed. According to the framework, four key modules are designed: a semantic edge enhancement module (SEEM) realizes boundary preliminary positioning through space-channel self-attention; on the basis of SEEM, a frequency domain feature guide enhancement module (FTEM) further improves boundary prediction precision by using Fourier transform and adaptive frequency selection; an adaptive edge feature module (AEFM) highlights key boundary features; a Context Attention Aggregation Module (CAAM) implements feature fusion. Experiments show that evaluation indexes of the method on data sets of Kvasair-SEG, ISIC2018 and KPIs2024 are remarkably improved, particularly, obvious advantages are shown when boundary fuzzy areas are processed, and reliable support is provided for accurate segmentation of medical images.

The present disclosure provides a frequency selective reflector reflecting electromagnetic waves in a particular frequency band to a direction different from a regular reflection direction, the frequency selective reflector including a plurality of regions and a function of adjusting a reflected beam profile.

The invention relates to the field of electromagnetic functional composite materials, and particularly discloses a multi-layer composite structure flexible frequency selective surface material and a preparation method thereof. The ultra-high molecular weight polymer fiber-reinforced polymer-based composite material thin-film mechanical enhanced band-pass frequency selection array sequentially comprises an acrylic acid polyvinylidene fluoride organic polymer coating environment-resistant layer, a metal oxide organic film isolation layer, an ultra-high molecular weight polymer fiber-reinforced polymer-based composite material thin-film mechanical enhanced layer, a band-pass frequency selection layer and a packaging protection layer from top to bottom, and the band-pass frequency selection layer is a hexagonal / circular ring nested band-pass frequency selection pattern array. The packaging protection layer is formed by printing a conductive coating composed of conductive filler / polymer resin matrix, and the packaging protection layer is an ink coating. The flexible frequency selective surface material has the characteristics of light weight, high strength, salt fog / rain / ultraviolet and other severe environments, frequency selective wave transmission and multiple functions, has good gas barrier property, is beneficial to maintaining the shape of an inflatable hangar made of a skin and ensuring normal operation of radar equipment, and has good practical engineering application value.

A system for material detection and identification including: an RF transmitter configured for transmitting into an environment an RF signal at a first resonance frequency for a target material, wherein the first resonance frequency is obtained from a material database associating each of a plurality of materials with one or more corresponding resonance frequencies; an RF receiver configured for receiving a resultant response signal from the environment; and a processor configured for: analyzing the resultant response signal for resonance characteristics that indicate a presence of the target material, wherein analyzing includes, if the resonance characteristics are detected and no other material in the material database shares similar resonance characteristics for the first resonance frequency, reporting to a user that the target material has been identified.

The invention discloses a method and a system for suppressing electromagnetic interference in multi-modal fusion touch interaction. The method comprises the following steps of: acquiring signal data, extracting signal features to obtain a first signal data set, and extracting interference source features to obtain interference source feature data; performing spectrum conflict analysis according to the interference source characteristic data to obtain a conflict frequency range; when the conflict frequency range exceeds a preset frequency threshold value, performing dynamic frequency selection and sensor parameter adjustment to obtain a second signal data set, and performing intensity detection to obtain residual interference intensity; when the residual interference intensity is higher than a preset intensity threshold value, carrying out dynamic encryption operation to obtain an encrypted signal flow, and carrying out key dynamic updating and optimization to obtain an anti-interference touch signal flow; and according to the anti-interference touch signal flow, performing interference suppression effect quantification to obtain a final performance evaluation result of electromagnetic interference suppression. The method can realize real-time high-reliability electromagnetic interference suppression in a complex human-computer interaction scene.

The present disclosure provides a frequency selective reflector reflecting electromagnetic waves in a particular frequency band of 24 GHz or more in a direction different from a regular reflection direction, the frequency selective reflector comprising: a reflecting member reflecting the electromagnetic waves; and a dielectric layer that is disposed at an incident side of the electromagnetic waves with respect to the reflecting member and transmits the electromagnetic waves, the dielectric layer has two types of thicknesses, and includes a plurality of first regions with thinner thickness and a plurality of second regions with thicker thickness.

An antenna system includes a first antenna and a second antenna. The first antenna includes a first radiating element, a first frequency selective surface, and a first feed network. The first radiating element is disposed on a side of the first frequency selective surface, and the second antenna is disposed on a side that is of the first frequency selective surface and that is away from the first radiating element. The first frequency selective surface includes a plurality of first strip-shaped structures and a plurality of second strip-shaped structures. The first strip-shaped structures and the second strip-shaped structures are made of metal. The plurality of first strip-shaped structures intersect with the plurality of second strip-shaped structures to form a plurality of grids. The first feed network includes a first structure, and the first structure is disposed on the first strip-shaped structure.

The invention relates to the technical field of radar measurement, in particular to a radar height measurement and radio frequency transceiving integrated system which comprises a signal processing module, a channel linkage scheduling module, a path stability judgment module, a frequency distribution management module and a positioning path feedback module. According to the invention, through amplitude peak point and time drift extraction, energy sudden change identification precision is enhanced, signal feature discrimination is improved, a screening channel is matched by using a beam main lobe and an energy center, efficient coupling of direction and energy is realized, path stability analysis introduces power attenuation and energy continuity evaluation, and available section identification accuracy is improved. The signal-to-noise ratio and the channel stable value are considered in frequency selection, the path spectrum utilization continuity is enhanced, frequency mapping is combined with round-trip time difference and height point coverage, the vertical positioning precision and the beam drop point judgment capability are improved, and the adaptability and reliability of radar measurement in a dynamic environment are integrally enhanced.

The invention relates to the technical field of mobile wireless network communication, and provides a multi-hop wireless ad hoc network and a centerless distributed frequency selection networking transmission method thereof. The method comprises the steps of networking control based on a service frequency hopping channel, spectrum sensing and spectrum evaluation, frequency selection negotiation based on neighbor nodes, time-frequency resource scheduling based on frequency selection, and frequency selection optimization based on data transmission. On the basis of TDMA channel access design, a networking control mechanism based on a service frequency hopping channel is designed, and nodes dynamically select available frequency channels for network service transmission in a distributed mode. Available frequency spectrum information is obtained through autonomous frequency spectrum sensing and frequency spectrum evaluation of nodes, frequency selection negotiation is performed between adjacent network nodes, and dynamic scheduling use of time-frequency two-dimensional resources is performed in combination with a frequency selection result, so that data transmission of network centerless distributed self-adaptive frequency selection is realized; and the reliable networking and communication capabilities of the network in a complex electromagnetic interference environment are enhanced.

The invention discloses a table data frequency domain anomaly detection method based on wavelet decoupling and adaptive reconstruction, and belongs to the technical field of anomaly detection. Aiming at the problems of insufficient utilization of data relevance and neglect of frequency domain mode difference in the prior art, spectrum decoupling is realized by constructing a Beta wavelet filter bank, and detection is performed in combination with an adaptive frequency selection module and a full-band reconstruction mechanism. The method specifically comprises the following steps: (1) constructing a table graph model based on a thermonuclear function, and quantifying node relevance; (2) realizing multi-scale frequency domain decomposition by adopting a compact support Beta wavelet, and separating a normal data core mode; (3) designing an alternating encoder-attention architecture, and dynamically screening key frequency components; and (4) constructing an anomaly scoring system through the reconstruction error. Through verification of 23 cross-domain reference data sets, the AUC-ROC and AUC-PR indexes of the method are averagely improved by 8.92%, and the method is remarkably superior to the prior art. The provided Rayleigh quotient purity index provides a quantification tool for spectrum energy distribution analysis, and reveals the strong correlation between frequency selection and spectrum energy.

The present invention relates to the field of high-rate mobile wireless communications. Disclosed are a multi-frequency multi-polarized wide-beam scanning base station system, and an optimization design method. The method comprises: on the basis of an aperture field expansion theory and a mode coupling theory, designing a conical horn feed source antenna capable of radiating a Gaussian fundamental mode beam, and providing a stable beam width and a stable phase center; designing a beam separation device based on a periodic structure, wherein the beam separation device includes band-pass frequency selective surfaces and a linear polarization grid; and combining front-end quasi-optical links of multiple frequency channels and multiple polarized channels, so as to increase the bandwidth and communication rate of a base station antenna. In the present invention, a genetic optimization algorithm is combined with reflector shaping, thereby effectively reducing the conflict between a shielding effect of a dual-reflector antenna and a scanning angle, and realizing the multiplication of a beam scanning angle.

Network Slice Selection Assistance Information (NSSAI) may be signaled between User Equipment (UE) and a network. NSSAI sent from the network to the UE may include, for example, Operating Frequency Band (OFB) for each Single NSSAI (S-NSSAI) in the NSSAI, as well as a Radio Access Technology (RAT) Frequency Selection Priority (RFSP) index, which the network configures as a part of UE access and mobility subscription, during a UE registration procedure. RAT restrictions may be enhanced to indicate to the UE that certain slices are not accessible via certain RATs. A UE may be provided by the network with an alternative NSSAI and corresponding OFBs for each S-NSSAI, thereby indicating to the UE that these S-NSSAI would have been allowed had they been requested. A UE may be able to choose an alternative Allowed NSSAI and send a registration update request to the network.

Methods, systems, and devices for wireless communications are described. An access point (AP) may update a bitmap (e.g., an extremely high throughput (EHT) operations (Ops) information element (IE) disabled subchannel bitmap) that indicates which channels of a band are available and unavailable. In some examples, the AP may update the bitmap during a channel availability check (CAC) based on whether various channels are DFS channels or non-DFS channels. During the CAC, the AP may transmit beacons to one or more stations (STAs) on the available non-DFS channels (e.g., instead of waiting until after the CAC to perform any beaconing).

The invention discloses a space short wave intelligent frequency selection system and a space short wave intelligent frequency selection method. The system comprises an airborne communication control system, an air-used short-wave radio station, an air-used short-wave antenna and laser inertial navigation equipment. The method comprises the following steps: an air-used short-wave radio station establishes a frequency forecasting model by using a machine learning technology according to time position information; the air-used short-wave radio station obtains a short-wave frequency band available frequency spectrum hole and puts the hole into a sky wave preselected frequency set, and a current passable frequency band is calculated in combination with a frequency forecasting model; the air-used short-wave radio station selects a frequency point with the minimum local electromagnetic interference from the preselected frequency set of the passable frequency band in combination with the local noise distribution condition to perform frequency selection and link establishment; the two parties store and sort the signal-to-noise ratios of the link establishment frequencies, and link establishment is completed if one pair of receiving and transmitting frequencies of the two parties meets communication requirements; and if not, returning to carry out the frequency selection process again until the frequency meeting the communication requirement is selected. According to the invention, automatic intelligent real-time frequency selection is realized, and the efficiency of frequency selection and link establishment and the passability of an air-service short-wave communication system are improved.

The invention discloses a parallel constant-voltage digital audio power amplifier and a broadcasting system. Comprising a line input module, a line output module, a first analog-to-digital conversion circuit, a second analog-to-digital conversion circuit, a third analog-to-digital conversion circuit, a digital signal processor, a single-chip microcomputer, a digital-to-analog conversion circuit, an error comparator, a modulator, an integrating circuit, a pulse width modulation input half-bridge output stage, and a first carrier frequency selection and gain adjustment module. A second carrier frequency selection and gain adjustment module, a first LC filter, a high-frequency compensation network, a communication bus and a power switch. The technical problems that an existing multi-channel parallel digital constant-voltage power amplifier is only limited to power amplifier channels in the same power amplifier, the parallel connection mode only uses the first channel as a main power amplifier and only uses the other channels as slave power amplifiers, and certain limitation exists are solved.

A microwave filter arrangement (100) for quantum computing applications, the filter arrangement (100) comprising a first port (113) and a second port (114). The microwave filter arrangement (100) comprises a main waveguiding structure (110) arranged between the first (113) and second (114) port, where the main waveguiding structure (110) comprises an inner conductor (111) having a circular cross-section that is surrounded by a hollow outer conductor (112) having a rectangular cross-section with two opposed long sides and two opposed short sides. The waveguiding structure (110) comprises a plurality of hollow waveguides (115) extending away from one or both of the long sides of the outer conductor, the hollow waveguides (115) comprising a dielectric material (122) and being terminated by an electromagnetically absorptive material (124).

Techniques for selecting frequencies of operation are described. HF signals may land at the receiver node with power levels dependent upon the transmit frequency. The frequency with the highest power level at the receiver node may be selected when the receiver node is not subject to interfering. The receiver node may be unable to receive a desired signal if an interfering signal has a signal level which is higher than the desired signal. The transmitter node may select a frequency which has a receiver signal level which is higher than the interfering signal for the selected frequency. The receiver node may then receive the transmit signal at the selected frequency even when subject to interfering from the interferer node.

A frequency selection surface manufacturing method based on femtosecond laser induced graphene belongs to the technical field of frequency selection surface manufacturing and comprises the following steps: (1) graphene patterning: forming a graphene periodic micro-nano structure on the surface of a flexible substrate through induction by femtosecond laser; (2) a frequency selection unit structure design step: a nested resonance structure is obtained by layering and stacking graphene resonance units with different geometrical shapes, and selective transmission or reflection of multi-band electromagnetic waves is realized; the graphene resonance unit is the graphene periodic micro-nano structure; and (3) a large-area manufacturing step: processing a frequency selection surface with the area larger than 10cm < 2 > by adopting femtosecond laser dynamic scanning and energy regulation and control technologies. According to the invention, the local structure modification of the graphene is induced by femtosecond laser, and the metasurface design is combined, so that the large-area and multi-band frequency selection characteristic is realized.

The invention discloses a band-pass type active frequency selective surface based on double-element composite loading. The band-pass type active frequency selective surface comprises at least one resonance unit which is periodically arranged, the resonance unit sequentially comprises a top metal frequency selection surface layer, a first dielectric structure layer, a middle metal feed layer, a second dielectric structure layer and a bottom metal frequency selection surface layer from top to bottom; the top metal layer and the bottom metal layer are composed of square ring aperture grooves subjected to deformation processing, and the middle feed layer is of a cross zigzag metal structure, plays a role in coupling an electromagnetic field and serves as a bias network of the AFSS. And the metal through holes penetrate through the resonance units in the vertical direction, so that the middle layer feeder line can respectively provide reverse bias voltage for independently regulating and controlling the resonance frequency for the PINs and the variable capacitance diodes on the top layer and the bottom layer. According to the invention, the functions of band switching and wide-range frequency tuning can be met, so that the problem of insertion loss increase caused by limited design frequency regulation and control range and element loading of the AFSS in the prior art can be solved.

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 communication, and discloses an AI-based adaptive data encryption method and system, and the method comprises the steps: carrying out the frequency domain transformation analysis of an original data flow, and generating a spectrum distribution feature set; the carrier frequencies are screened through a dynamic frequency selection algorithm to obtain an optimal carrier frequency range; performing phase modulation on the data bit stream, and embedding the data bit stream into a subcarrier in an optimal carrier frequency range to generate a first encrypted data stream; when the interference intensity exceeds an interference threshold value, performing directional adjustment on a frequency deviation parameter according to an interference type, and generating a second encrypted data stream; dynamically adjusting the frequency distribution parameters according to the transmission distance data to obtain a frequency distribution parameter set; and performing adaptive modulation and spectrum shaping on the second encrypted data stream based on the frequency distribution parameter set, and outputting a hidden transmission data stream. The method has the following effect that the data hidden transmission capability and the receiving and restoring accuracy in a complex environment can be improved.

The invention provides a continuous time linear equalizer based on a low-pass and band-pass mixed structure. The continuous time linear equalizer comprises a frequency selection coupler, a low-pass transconductance unit, a band-pass transconductance unit and a load unit. The frequency selection coupler is used for separating the differential analog signal into a first voltage component in a first band-pass frequency range and a second voltage component in a low-pass frequency range, the first band-pass frequency range comprises a target frequency expected to be compensated, and the frequency in the first band-pass frequency range is greater than the frequency in the low-pass frequency range; the band-pass transconductance unit is used for converting the first voltage component into current and synchronously realizing gain amplification to obtain a first current signal; the low-pass transconductance unit is used for converting the second voltage component into current and synchronously realizing gain amplification to obtain a second current signal; the load unit is used for summing the first current signal and the second current signal and converting the sum to a differential output voltage signal. According to the invention, the frequency corresponding to the gain peak point and the gain amplitude can be improved.

The invention provides an antenna system and a base station antenna feeder system. The antenna system comprises a first frequency band radiation unit array, a frequency selection surface and a second frequency band radiation unit array which are arranged in sequence, that is, the frequency selection surface is arranged between the first frequency band radiation unit array and the second frequency band radiation unit array. The frequency selection surface is used for reflecting signals of the first frequency band radiation unit array and transmitting signals of the second frequency band radiation unit array. The phase shifter is connected with the first frequency band radiation unit array so as to be used for feeding the first frequency band radiation unit array. The phase shifter comprises a cavity, the cavity is arranged at the edge of the frequency selection surface, and the first extension direction of the cavity is consistent with the second extension direction of the first frequency band radiation unit array. The antenna system at least comprises the radiation unit arrays of the two frequency bands, the signal quality of the antenna system is good, and the integration level is high. Further. The radiation unit arrays of different frequency bands can be independently evolved.

The present disclosure provides a protective enclosure for electronic systems. The enclosure comprises a polymer-containing matrix and a metamaterial incorporated into the matrix. The metamaterial is tuned to a specific permittivity or permeability to absorb or reflect a particular frequency. The protective enclosure may be used to create a safe inner environment for electronic components while facilitating uninterrupted wireless communications to / from the outer environment. Additionally, the protective enclosure may be used to protect against electromagnetic interference. In particular, shielding metamaterials are configured individually or in combination to specifically shield (via reflection, absorption, etc.) against relatively wide bands of electromagnetic frequencies, while transparent metamaterials are configured specifically to pass electromagnetic signals within narrow bands of frequencies. This new approach resolves and vastly improves current shield solutions, such as Faraday cages. For example, tuned metamaterials may be configured across a variety of preconfigured frequencies, and can be constructed of lightweight materials.

The invention relates to the technical field of wireless communication, and provides a low-earth-orbit satellite link state management and optimization method, which comprises the following steps of: acquiring communication windows and signal intensities of different low-earth-orbit satellite links by adopting a link prediction method, and further judging whether the satellite links are available or not; when the satellite link is unavailable, a standby satellite is selected in advance, and the optimal switching opportunity is determined; the terminal selects the optimal frequency band for communication in real time according to the current link quality, the satellite signal strength and the interference condition, and dynamically allocates satellite frequency band bandwidth resources by adopting a dynamic frequency selection method; and adjusting a signal modulation mode and a coding rate according to the signal quality. According to the invention, the terminal can select the standby satellite in advance and complete seamless switching before the current link fails, so that the delay and interruption time of link switching are remarkably reduced. The utilization efficiency of spectrum resources is improved by adopting a dynamic frequency selection and bandwidth resource allocation technology, and the anti-interference capability of a communication link in a complex environment is enhanced.

The invention discloses a photon counting laser radar non-vision target reconstruction system and method, and the method comprises the steps: enabling a photon counting laser radar to be aligned with an intermediate surface, and controlling the photon counting laser radar to detect a relay surface and a target; counting the received photon signals to obtain a photon histogram of a first echo signal and a target signal of a relay surface, and improving the time resolution by adopting a hybrid regularized Richardson-Lucy deconvolution algorithm; carrying out peak value extraction by utilizing the echo signal of the relay surface, and calculating relative coordinates of sampling points on the non-flat relay surface in combination with a laser emission angle; analyzing the spectral characteristics of the photon histogram of the target echo signal, adaptively obtaining an effective frequency range for reconstruction, and giving weight distribution; a target signal is processed in combination with a frequency-selecting window, and then a non-vision-field target reconstruction algorithm of diffraction interpolation is utilized to realize reconstruction of a hidden target. The method has universality for non-vision field target reconstruction of various relay surface shapes, sparse modes and sparse rates, and can realize complete and clear reconstruction of hidden targets.