239 results about "Frequency selectivity" patented technology

The invention discloses a bionic TENG sensor unit for an artificial throat and a preparation method thereof, and relates to the field of artificial throats, and the sensor unit comprises a gradient micro-dome friction layer, a strain amplification layer, an electrode layer and a back cavity substrate layer. The gradient micro-dome array realizes gradual contact through gradient change of height and diameter; the strain amplification layer converts vertical vibration into horizontal strain by using a cantilever beam-sliding block structure; the back cavity array selectively amplifies vibration at a specific frequency based on the Helmholtz resonance principle. The invention further provides a corresponding preparation method. The preparation method comprises the steps of back cavity forming, electrode deposition, microstructure manufacturing, surface treatment and the like. The sensor has the advantages of high sensitivity, good frequency selectivity and strong durability, and is particularly suitable for detecting weak laryngeal vibration signals of laryngeal patients.

The invention discloses an OCT (Optical Coherence Tomography) retina image denoising method based on a high-frequency enhanced diffusion model, which is characterized in that a double-branch diffusion model network constructed based on frequency perception Fourier transform attention (FFTA) is used for separating different frequency domains, enhancing specific frequency domain features and fusing the specific frequency domain features into a spatial domain feature map to realize stronger frequency domain perception and processing capability; the invention relates to a time step T coding method for a module of frequency domain attention. The time step T of the diffusion model is used as a parameter to be coded into a frequency domain attention module to participate in self-attention matrix calculation, so that frequency domain feature processing is aligned with the iteration step number of the diffusion model, and different frequency domain information is pointedly processed at different time steps T; the frequency selective hopping mechanism uses pooling operation to obtain a high / low frequency characteristic pattern, so that the network has adaptive frequency domain retention capability for different local parts.

The invention provides an electric connector signal transmission optimization method and system, and relates to the technical field of communication, and the method comprises the steps: obtaining an electrical characteristic parameter and transmission path topological information, recognizing a frequency turning point, calculating a loss coefficient, constructing a frequency selectivity compensation mapping rule, and obtaining a frequency division compensation strategy; and calculating a double-component correction factor, carrying out nonlinear adaptive adjustment to obtain a target compensation parameter, and finally generating a multi-path compensation control signal. According to the invention, loss characteristics in signal transmission can be accurately identified, frequency selective compensation is realized, and the signal transmission quality and stability of the electric connector are improved.

The disclosure deals with system and method for discerning the radius maximizing reliability for binary modulation on conjugate-reciprocal zeros (BMOCZ) implemented with both a maximum likelihood (ML) and direct zero-testing (DiZeT) decoder. The optimal radius for BMOCZ is disclosed to be a function of the employed decoder. The radius maximizing the minimum distance between polynomial zeros does not maximize the minimum distance of the final code. While maximizing zero separation offers an almost optimal solution for the DiZeT decoder, the ML decoder outperforms the DiZeT decoder in both additive white Gaussian noise (AWGN) and fading channels when the radius is chosen to maximize codeword separation. Different sequence-to-subcarrier mappings for BMOCZ-based orthogonal frequency division multiplexing (OFDM) are analyzed to highlight a flexible time-frequency mapping approach that avoids distortion introduced by a frequency-selective channel at the expense of higher peak-to-average power ratio (PAPR).

The invention provides a component high-frequency signal transmission quality prediction and optimization method and system, and relates to the technical field of signal transmission, and the method comprises the steps: extracting the attenuation change rate of each frequency band based on the frequency domain characteristics and transmission path physical characteristic parameters of a to-be-transmitted signal of a component, and building a correlation function with a frequency band boundary position; calculating a transmission path terminal prediction loss spectrum and determining a compensation gain coefficient; performing frequency selective amplitude adjustment on the to-be-transmitted signal; and an actual received signal is collected and compared with the target frequency domain amplitude distribution, and the correlation function is updated. According to the invention, accurate prediction and adaptive optimization of high-frequency signal transmission quality are realized, and signal transmission integrity is improved.

A tuned-frequency-spectrum earpiece for selectively tuning audio frequencies that enter an inner ear of a user wearing the earpiece, the earpiece including a base having an emitter end and receiver end, the base including a channel that passes through an entirety of the base; a sound-attenuation plug, wherein the sound-attenuation plug is configured to couple to the base such that the sound-attenuation plug surrounds at least a portion of the channel of the base; a first filter device configured to insert into the channel of the base and to selectively reject undesired frequencies of the audio frequencies that enter the earpiece; and a frequency-selective sound collector operatively coupled to the receiver end of the base and configured to increase an amount of desired frequencies of the audio frequencies that enter the first filter device. Some embodiments increase the amount of sound from some directions while reducing sound from other directions.

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 discloses a space-time modulation filtering circulator based on a substrate integrated waveguide, which consists of a top metal patch, a dielectric substrate, a bottom metal floor, a large metalized through hole and a small metalized through hole, and comprises a rectangular SIW cavity I, a rectangular SIW cavity II, a rectangular SIW cavity III, a pentagonal SIW cavity I, a pentagonal SIW cavity II, a pentagonal SIW cavity III and a circulator central junction, the rectangular SIW cavities are traditional SIW cavities resonating in a fundamental mode, and the pentagonal SIW cavities are space-time modulation SIW cavities; the pentagonal SIW cavity I, the pentagonal SIW cavity II and the pentagonal SIW cavity III are coupled and cascaded through a circulator central junction; the rectangular SIW cavities I, II and III are cascaded with the pentagonal SIW cavities I, II and III in a magnetic coupling mode; the rectangular SIW cavity I, the rectangular SIW cavity II and the rectangular SIW cavity III are fed by the coplanar waveguide transmission line I, the coplanar waveguide transmission line II and the coplanar waveguide transmission line III; according to the space-time modulation SIW filtering circulator provided by the invention, ferrite materials are not needed, the circulator function is realized by adopting three tuning elements, the design complexity of the space-time modulation circulator is reduced, and the frequency selectivity is improved.

The invention discloses a low-profile low-RCS (radar cross section) circular polarization double-folded transmission array antenna, which comprises a wave-absorbing type frequency selection polarizer and a double-folded transmission array antenna, and is characterized in that the wave-absorbing type frequency selection polarizer is positioned above the double-folded transmission array antenna; the wave-absorbing type frequency selection polarizer comprises a loss layer and a linear circular polarization converter with a frequency selection characteristic, wherein the loss layer and the linear circular polarization converter are separated by an air gap layer; the double-folded transmission array antenna comprises an integrated reflection-transmission metasurface and a polarization conversion metasurface, and the integrated reflection-transmission metasurface and the polarization conversion metasurface are separated by an air gap layer. According to the circularly polarized antenna, the single-station RCS reduction performance of more than 10 dB is achieved within the broadband range of 6.8-21.9 GHz, meanwhile, the radiation gain can be improved, the profile can be reduced, and the circularly polarized antenna has the advantages of being wide in band, low in profile, high in gain and low in RCS.

Wireless communications systems and methods related to wireless communications in a system are provided. A user equipment (UE) may receive from a base station (BS), an uplink (UL) scheduling grant indicating subband precoding information and a resource allocation spanning a plurality of subbands. The UE may determine a plurality of subband precoders based on the subband precoding information. Each precoder of the plurality of subband precoders may be associated with a subband of the plurality of subbands. The UE may transmit to the BS, an UL communication signal in the resource allocation using the plurality of subband precoders.

The invention belongs to the technical field of integrated circuits, and discloses a high-selectivity constant-bandwidth reconfigurable filter chip based on a GaAs (gallium arsenide) process, which comprises a dielectric substrate, a multilayer metal structure, a plurality of folded opening-shaped metal microstrip lines, a plurality of grounding metal columns, a variable capacitance diode, an MIM (metal injection molding) capacitor and the like. Resonance is realized in a mode of combining electric coupling and magnetic coupling, a variable capacitance diode is utilized to tune the center frequency, and the bandwidth is kept constant in the tuning process. Transmission zeros are introduced at two sides of a passband through cross coupling, so that the frequency selectivity and the spectrum management capability are remarkably improved, and meanwhile, the optimization of the microstrip interconnection structure effectively reduces the system loss. According to the invention, the strict requirements of a modern radio frequency communication system on miniaturization, high performance and high selectivity can be met, and extremely high adjustability and adaptability are achieved.

The invention discloses a high-isolation and high-selectivity filtering power divider with an input end broadband non-reflection characteristic. Comprising an input port, two output ports, a double-L-shaped non-reflection absorption structure, two microstrip connecting lines, two parallel coupling lines, two L-shaped step resonators, two non-reflection absorption isolation resistors, a quarter-wavelength parallel coupling connecting line and two U-shaped transmission lines. The input port is a first port; the two output ports comprise a port II and a port III; the double-L-shaped non-reflection absorption structure comprises a first non-reflection absorption resistor, a second non-reflection absorption resistor, a first L-shaped non-reflection absorption connecting line and a second L-shaped non-reflection absorption connecting line. According to the invention, the broadband reflection-free absorption characteristic of the input end and the broadband high isolation between the output ports are realized at the same time, a plurality of transmission zeros are introduced through the L-shaped step resonators, and the frequency selectivity and out-of-band rejection are improved.

The invention discloses a low-voltage power line carrier communication network repeater deployment method and system, and relates to the technical field of power communication. The method comprises the following steps: (1) according to PLC network topology information, acquiring an STA set which cannot directly communicate with a CCO, and inputting model parameters; (2) calling a general optimization solver to carry out model solution to obtain a solution result; (3) if the feasible solution exists, outputting a PCO deployment mark; if not, adjusting the received signal threshold value and the transmitting power, and repeating the step (2); and (5) once a feasible solution is obtained or the model parameter reaches the set limit value, the solution is ended. According to the deployment planning model constructed by the invention, the optimal deployment position of the PCO in the network is solved by taking the minimum weighted sum of the total transmission time delay and the total cost as a target and taking the received signal strength and the single-hop relay as constraints; the problem that seamless coverage of a low-voltage power distribution network is difficult to realize by single-hop communication due to high background noise and frequency selective fading of a PLC channel is solved.

The present invention provides an interleaving method and a related device for mapping a virtual resource block to a physical resource block (VRB-to-PRB) during a sub-band full duplex (SBFD) period, and a method for mapping a virtual resource block to a physical resource block (VRB-to-PRB) during the SBFD period of the sub-band full duplex (SBFD) period of the sub-band full duplex (SBFD) period of the sub-band full duplex (SBFD) period of the sub-band full duplex (SBFD) period of the virtual resource block to the physical resource block (VRB-to-PRB). In one embodiment, the method includes performing a VRB-to-PRB interleaving during the SBFD to interleave resource blocks (RBs) and map a VRB beam to a PRB beam in a first DL frequency domain and a second DL frequency domain. By the method, the VRB-to-PRB interleaving is enhanced in the SBFD operation, thereby being able to benefit from less frequency selective fading.

The invention discloses a coding and decoding method for LDPC codes under time and frequency selective channels in an NAVDAT system, and the method comprises the steps: determining a basis matrix and an expansion factor Z according to an information bit length and a target code length of an input bit sequence before coding, and the Z is a positive integer; obtaining a low density parity check (LDPC) matrix based on the basis matrix and the expansion factor Z; the method comprises the following steps: encoding an input bit sequence by using a low density parity check (LDPC) matrix under an NAVDAT system time and frequency selective channel, wherein the code rate is 3 / 4 or 1 / 2; wherein a basis matrix of the LDPC matrix comprises a sub-matrix A and a sub-matrix B, if the basis matrix is expressed as an m-row n-column matrix, the sub-matrix A is an m-row n-m-column matrix, the sub-matrix B is an m-row m-column matrix, and the sub-matrix B comprises a double-diagonal structure matrix B1, a single-diagonal structure matrix B2 and a column B3 with the weight of 4; and outputting the coded or decoded bit sequence. According to the invention, the coding requirements of information bit sequences with various lengths can be met.

The application provides a design method of a broadband multi-modal vibration suppression damping material based on fractal geometry, comprising: constructing an initial geometric configuration of the damping material, the damping material being composed of a periodic arrangement of a three-dimensional unit cell structure in a plane; layering the unit cell structure to construct a parameterized model of the unit cell structure by using a fractal dimension of the unit cell structure and layer structure parameters; constructing a vibration impedance transfer equation according to the parameterized model of the unit cell structure, determining input impedances of the innermost layer and the outermost layer, and determining vibration attenuation amounts of the unit cell structure in multi-target frequency bands by using the input impedances of the innermost layer and the outermost layer; and optimizing the configuration and the parameterized model of the unit cell structure until the vibration attenuation amounts of the unit cell structure in the multi-target frequency bands meet load platform requirements. The broadband multi-modal vibration suppression damping material based on fractal geometry constructed can realize efficient dissipation of 10-1000 Hz broadband vibration energy and solve the frequency selectivity limitation of traditional homogeneous damping materials in multi-frequency vibration suppression.

The application relates to the technical field of tunable N-path filter, in particular to a tunable N-path reflection-free filter and a superheterodyne receiver. The tunable N-path reflection-free filter comprises a signal source, an N-path band-pass filter unit, an N-path band-stop filter unit, an output resistor and a phase-splitting clock generating circuit. The output end of the signal source is connected with one end of the N-path band-pass filter unit and the N-path band-stop filter unit respectively, the other end of the N-path band-stop filter unit is connected with the output resistor, the gate of a plurality of MOS switches in the N-path band-pass filter unit and the N-path band-stop filter unit is connected with the phase-splitting clock generating circuit, and the phase-splitting clock generating circuit outputs a control signal. The tunable N-path reflection-free filter provided by the application has excellent frequency selectivity, can effectively suppress high-order harmonics, and can adjust the passband and the stopband by changing the switching frequency. Meanwhile, the filter can eliminate the reflected signal, prevent the intermodulation interference and gain fluctuation of the mixer and the high-gain amplifier in the system.

Apparatuses and methods for frequency selective beam management (FSBM). A method for operating a user equipment (UE) includes receiving first information indicating one or more channel state information (CSI) reference signal (RS) resources for FSBM and receiving second information indicating a correspondence between the one or more CSI-RS resources and a plurality of frequency subbands. The method further includes determining, based on the first information, the one or more CSI-RS resources for FSBM and identifying, based on the second information, the correspondence between the one or more CSI-RS resources and the plurality of frequency subbands.

The present disclosure provides a signal generation method, device and communication system, relating to the technical field of wireless communication and terminal. The method comprises: generating a first binary keying signal OOK waveform based on a low-power wake-up LP-WUS signal, replacing part of the waveform of each period in the first OOK waveform with a constant modulus sequence to obtain a target waveform, the constant modulus sequence being a group of sequences with the same modulus but different phases. According to the embodiment of the present disclosure, the first OOK waveform generated based on the LP-WUS signal can be scattered, the frequency diversity gain of the LP-WUS signal is improved, a similar spread spectrum effect is formed, so that the signal can still have good performance when passing through a frequency selective fading channel (such as TDL-C), so as to improve the detection accuracy and detection efficiency of the LP-WUS signal, and further improve the synchronization of NR reception and reduce energy loss.

This invention discloses a single-polarization broadband signal anti-reflection power-generating glass, an etching method, and an installation method, relating to the fields of communication and photovoltaic power generation technology. The power-generating glass includes an ultra-clear glass substrate and a plurality of single-segment thin-film solar cells connected in series within a layer of the ultra-clear glass substrate. Each single-segment thin-film solar cell includes a positive electrode, a power-generating thin film layer, and a back electrode. The positive electrode, power-generating thin film layer, and back electrode are sequentially stacked and bonded along the thickness direction of the ultra-clear glass substrate, and each is etched with periodically arranged rectangular patterns. The long side of each rectangular pattern is horizontal, forming a frequency-selective surface for the penetration of vertically polarized electromagnetic signals. This invention, by etching rectangular patterns on the power-generating glass, achieves efficient transmission of signals in the target frequency band while ensuring power generation functionality, solving the problem of traditional power-generating glass blocking communication signals and improving the quality of broadband signal transmission.

A method for making an uncoated fine mesh design on a coated surface. The aim of this design is to completely or partially reflect or transmit specific frequencies of the electromagnetic spectrum. Such design is referred to as a frequency selective surface (FSS). More particularly, the invention relates to masking a portion of the surface of the substrate prior to deposition of the coating and later removing the mask by water washing in the process, leaving the designed fine mesh FSS pattern.

This invention discloses a system and method for acoustic wireless communication that eliminates frequency-selective fading and delay spread. Addressing the problems of frequency-selective fading and delay spread in acoustic wave transmission within the water-based drilling fluid channel inside the drill pipe, it employs orthogonal frequency division multiplexing (OFDM) technology. The transmitting end includes a coding and modulation module, an OFDM modulation module, a power amplification unit, an impedance matching network, and an underwater acoustic transducer. The receiving end includes a synchronization module, a cyclic prefix removal module, a Fourier transform module, a channel estimation module, a channel equalization module, and a decoding module. The synchronization module uses the Schmidl & Cox time-frequency joint synchronization algorithm, the channel estimation module uses the MMSE frequency domain estimation algorithm based on training sequences, and the channel equalization module uses the linear MMSE frequency domain equalization algorithm. Through the co-design of hardware and algorithms, this invention effectively eliminates frequency-selective fading and delay spread, achieving high-speed, low-error-rate acoustic wireless transmission. The data transmission rate can reach 250 kbit / s, and the bit error rate can be reduced to 10%. ‑3 .

The invention is applicable to the technical field of communication, and provides a frequency selection boundary and a multi-frequency array antenna, which comprises a reflecting plate, low-frequency radiation units, high-frequency radiation units and a frequency selection boundary, and is characterized in that the high-frequency radiation units are symmetrically distributed by taking the midpoint of the reflecting plate as the center to form a high-frequency array; the low-frequency radiation units are nested between two rows of adjacent high-frequency radiation units to form a low-frequency array, and the frequency selection boundary is arranged at the center of the reflecting plate. Therefore, according to the frequency selection boundary and the multi-frequency array antenna provided by the invention, good radiation of each frequency band of the multi-frequency antenna is ensured.

The present invention relates to an antenna arrangement comprising a first antenna patch panel that emits an operating frequency of a first frequency band, and at least one second antenna patch panel that emits an operating frequency higher than the first frequency band, where the first antenna patch panel comprises a frequency selective transmission pattern portion, the frequency selective transmission pattern part is used for transmitting a wave beam (hereinafter referred to as a middle wave beam) of the working frequency transmitted by the second antenna patch panel, and is arranged in a middle wave beam transmitting direction opposite to the second antenna patch panel in a conductive pattern shape; and the first antenna patch panel is completely or at least partially overlapped with the part of the first antenna patch panel, so that the advantages of preventing the size of the product from being enlarged and improving the signal quality are provided.

This invention discloses a bandpass frequency-selective surface structure based on strongly coupled pairs, composed of multiple basic structural units. Each basic structural unit has a vertically symmetrical structure along its thickness direction. Both the upper and lower symmetrical portions include a first metal layer and a first dielectric layer in symmetrical positions. The first metal layer contains a first resonator pair, a second resonator pair, and a third resonator pair, each using metal patches as resonators. A second metal layer and a second dielectric layer, separated along the thickness direction of the basic structural unit and in asymmetrical positions, are disposed between the upper and lower symmetrical portions. The upper and lower symmetrical portions are connected by metal conductive posts. This invention operates stably at a center frequency of 5 GHz, introduces four transmission zeros, achieves a fourth-order frequency response within 8.4% of the relative bandwidth, has an insertion loss of less than 0.49 dB, and 40° angular stability, exhibiting superior performance.

A method of estimating a channel by a reception apparatus in a wireless communication system, includes estimating a reception channel based on a received signal; determining a signal-to-noise ratio (SNR) of the received signal; estimating a frequency selectivity of the reception channel; determining a moving average filter based on the SNR and the frequency selectivity; and applying the determined moving average filter to the estimated reception channel.

The application provides a high-selectivity and simple-structure filter power amplifier and radio frequency integrated circuit, and relates to the field of power semiconductor devices.The application provides stable gate and drain bias voltages for the power amplifier transistor through a gate DC bias network and a drain DC bias network, and guarantees stable operation of the device.The input end and the output end impedance matching network are symmetrically arranged around the power amplifier transistor, both of which contain the same filter impedance transformer, and the layout is compact and simple, without additional independent filter module, effectively simplifying the circuit structure and improving the miniaturization level.Further, the filter impedance transformer is formed by cascading two λ / 4 parallel coupled microstrip lines and is matched with a λ / 2 open microstrip line, and based on the transmission line impedance transformation principle, the filter impedance transformer realizes fundamental real impedance matching, reduces signal transmission loss, forms transmission zero points in the stop band, and significantly improves the frequency selectivity.The overall circuit has high integration, excellent performance, and good engineering application and promotion value.

The invention discloses a low-profile common-caliber base station antenna which comprises a metasurface antenna unit, a low-frequency cross dipole antenna is arranged on the upper end face of the metasurface antenna unit, and the low-frequency cross dipole antenna is arranged on the lower end face of the metasurface antenna unit while the metasurface antenna unit provides high-frequency-band signal radiation and performs wide-angle beam scanning. And the low-frequency cross dipole antenna is used for providing low-frequency-band signal radiation and carrying out fixed beam scanning so as to realize multi-frequency-band signal coverage. According to the invention, the frequency selectivity and the high and low frequency collaborative radiation performance of the cross dipole antenna can be improved.

The application discloses a wide-bandwidth non-reflective dual-frequency filter and particularly relates to the technical field of microwave communication, and solves the technical problem of signal reflection outside the working frequency band of the existing dual-frequency filter, and the complex structure, large volume, poor absorption effect and poor high-bandwidth effect of a small amount of non-reflective dual-frequency or multi-frequency filter, and the sacrifice of certain out-of-band suppression performance and insertion loss of the non-reflective dual-frequency filter while pursuing the non-reflective characteristic, especially the poor harmonic suppression in the transition area of the two frequency bands and the high-bandwidth area; the technical scheme is that a pair of quarter-wavelength coupled microstrip lines MCL1 and quarter-wavelength microstrip lines ML2 are connected in series, and three-quarter-wavelength microstrip lines ML1 and microstrip lines ML2 are connected in parallel to form a dual-band pass filter response; the application has the good absorption effect in the whole frequency band and enhances the frequency selectivity of the in-band signal.

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.