279 results about "Narrow bandwidth" patented technology

The invention provides a multi-path embedded video coding method and system based on generative artificial intelligence. The multi-path embedded video coding method comprises the following steps: firstly, coding input cue words and demand parameters, and outputting cue word vectors and demand parameter code streams; then decoding the cue word vector and the demand parameter code stream, and outputting a feature vector and a feature map; extracting the feature vector, the feature map and the representation guide vector to obtain multi-embedded feature information; reconstructing a picture by using the obtained multi-embedded feature information through a generative AI and obtaining a video to be iterated; performing video quality evaluation on the video to be iterated; and generating a binary code stream for transmission through the current cue word vector, the demand parameter code stream and the multi-embedded feature information input. According to the method, important information characteristics are transmitted in a highly abstracted manner, and a high-definition video is reconstructed at a receiving end, so that the storage space required by video coding and the size of a transmission information stream are greatly reduced, and higher-definition transmission under a narrower bandwidth is realized or video coding under an extremely low bandwidth becomes possible.

The technology described herein is directed towards modular metasurfaces arranged with unit cells for narrowband, wideband and / or multiband sound absorption, in which the unit cells are based on Helmholtz resonators that are deployed in a server rack, proximate to a server, without substantially obstructing airflow from the server fan(s). Each sound absorbing unit-cells is designed and constructed based on a specific resonance frequency, and includes a neck portion and air chamber dimensioned to resonate at the desired resonance frequency and thereby inverse phase cancel corresponding narrowband frequencies of incoming sound waves. Differently-dimensioned unit cells can be built into a single metasurface module, thereby facilitating wideband and / or multiband sound absorption with that metasurface. The modular metasurfaces can be attached to the sidewalls of a server rack, or positioned in otherwise empty slots above and below a server, optionally coupled to blanking panels for covering the openings of those slots.

The invention relates to an asymmetric transmission optical device, a test method and an electronic device, and belongs to the technical field of nano optics and photonics. Comprising a dielectric nano-particle array which comprises a plurality of dielectric nano-particles, and the dielectric nano-particles are periodically arranged according to a preset interval; wherein the height of the dielectric nano particles is 60 nm to 150 nm; and the dielectric substrate is arranged below the dielectric nanoparticle array. The test method comprises the following steps: establishing a periodic array model according to the optical device, and setting structural parameters of the model to obtain an optimal periodic array model; performing asymmetric transmission mechanism analysis and structural parameter analysis by using the optimal periodic array model; and according to an analysis result, obtaining an optimal structure parameter of asymmetric transmission. The problems of high loss, narrow bandwidth and polarization sensitivity are avoided, and the defects of high preparation difficulty, high cost and poor compatibility caused by a complex geometric structure or a specific material are overcome.

The invention discloses a negative group delay system based on SSPP, and belongs to the technical field of microwave communication. A fundamental mode negative group velocity is innovatively generated based on an artificial surface plasmon SSPP, and an SSPP system with negative group delay is realized. The system comprises two parts, namely an amplifier circuit and an SSPP waveguide with a negative group delay unit. The SSPP waveguide with the negative group delay characteristic comprises two coplanar waveguide parts, two transition parts and an SSPP waveguide part, the SSPP waveguide part comprises a unit for generating negative group velocity and a plurality of basic units, and further comprises a microwave dielectric substrate. The amplifier is composed of an amplifier chip, a peripheral capacitor inductor of the amplifier chip and a direct-current power supply. An input signal passes through the system, and advanced transmission of the signal can be realized. The problems of narrow bandwidth, large loss and non-adjustable structure in the prior art are effectively solved, and the antenna has wide application prospects in the fields of 5G communication, radar signal processing, array antenna systems and the like.

The invention discloses an ultra-large octave wave absorber based on a photoconductive material, and belongs to the field of electromagnetic metasurfaces and metamaterials. Comprising a light response wave-absorbing metasurface and a light driving module capable of projecting different patterns on the surface of the light response wave-absorbing metasurface, array wave-absorbing units of different sizes are obtained on the light response wave-absorbing metasurface by switching the projected patterns, and impedance of a target frequency band is matched by changing equivalent capacitance / inductance of a wave-absorbing unit structure; the light driving module can project a preset light pattern on the light response wave-absorbing metasurface, so that the equivalent impedance distribution of the light response wave-absorbing metasurface is changed; according to the light response wave-absorbing metasurface, the conductivity distribution of the metasurface units is changed through light control, and the wave-absorbing frequency band is adjusted in real time, that is, dynamic adjustment of the wave-absorbing performance is achieved through non-contact light control. According to the invention, the limitation of narrow bandwidth and passive fixation of a traditional wave absorber is broken through, and electromagnetic wave control with ultra-large octave, high absorptivity and real-time reconfigurability is realized.

A system includes an illumination system, an optical element, a switching element and a detector. The illumination system includes a broadband light source that generates a beam of radiation. The dispersive optical element receives the beam of radiation and generates a plurality of light beams having a narrower bandwidth than the broadband light source. The optical switch receives the plurality of light 5 beams and transmits each one of the plurality of light beams to a respective one of a plurality of alignment sensor of a sensor array. The detector receives radiation returning from the sensor array and to generate a measurement signal based on the received radiation.

According to the efficient data compression encryption and decryption method under the low-bandwidth condition, aiming at the characteristics of different data types, a specific compression algorithm is adopted to improve the compression ratio and the flexibility, and different encryption levels are adopted according to the data sensitivity degree to ensure the safety and the resource utilization efficiency. Meanwhile, by optimizing the time of all links such as compression, encryption, transmission, decryption and decompression, balance of the overall time is achieved, and therefore the overall efficiency of the system and the user experience are improved. According to the invention, some problems existing in data compression, encryption and decryption under the narrow bandwidth condition at present are effectively solved.

The endoscope light source lighting device comprises a light source assembly, a light source collimation module, a light combination assembly and an optical fiber coupling module, after light beams emitted by the light source assembly are collimated by the light source collimation module, the light beams are combined through the light combination assembly, and finally the light beams are coupled with optical fibers through the optical fiber coupling module. And one or more paths of light beams of the light source assembly are controlled to be coupled and output, illumination output in multiple illumination modes is achieved, and the multiple illumination modes comprise a white light illumination mode, a multi-narrow-band light illumination mode, a near-infrared light illumination mode and a composite light illumination mode. According to the multi-channel lighting mode, narrow-band or broadband spectrum composite lighting is achieved, the problems that in the prior art, the light emitting mode is limited, and high-color-rendering-index lighting light with continuous spectrums cannot be output in a white light lighting mode are solved, and the problems that original narrow-band lighting is low in efficiency, inflexible and poor in lighting effect are solved. And the requirement of flexible switching between narrow-band illumination and wide-band illumination cannot be met, and the illumination requirement of a detected part in clinical diagnosis and treatment is met.

The invention relates to the technical field of video compression, in particular to a narrow-bandwidth-based video monitoring data transmission and storage method, which comprises the following steps of: for an input video monitoring data frame, calculating a difference absolute value sum between a current frame and a reference frame; according to the method, the pixel difference of the current frame and the reference frame is calculated, and the average amplitude of the motion vector field is fused to form a comprehensive index of the dynamic degree of the quantized content, so that the image group structure is not fixed or periodic any more, and the dynamic degree of the quantized content can be calculated according to the score of scene activity and the change intensity. When a monitoring picture is static, a super-long image group is established to limit a compression code rate, when the picture is suddenly changed, the super-long image group is quickly switched to a short image group to ensure instant refreshing and definition of key information, meanwhile, non-uniform redistribution is performed on limited total code rate budget, bit resources can be intelligently inclined to frames with violent content change and large information amount, and the real-time refreshing and definition of the key information are ensured. Therefore, the subjective visual quality of the key dynamic moments is improved under the narrow bandwidth.

The invention belongs to the technical field of vibration conditions, and particularly relates to a crawler land constant-speed driving vibration condition correction method, crawler land constant-speed driving vibration data is often regarded as a whole to be processed as a random vibration condition to guide design and examination of parts on a vehicle, and an induction result is usually in a narrow-band + wide-band random form. However, when the crawler runs at a constant speed on the land, the frequency domain characteristic of the vibration data is closer to the form of'sine + broadband random ', and the method is suitable for correction of such vibration conditions. The accuracy of the vibration condition is improved, vibration environment distortion caused by discomfort of the induction method is reduced, and over-test or under-test of the induction vibration test is avoided. According to the invention, the narrowband component in the vibration signal is regarded as the projection of the sinusoidal signal in the power spectral density, the center frequency and the relative amplitude of the narrowband signal are calculated and converted into the frequency and the amplitude of the sinusoidal signal, and the narrowband component is replaced by the sinusoidal component, so that more accurate vibration test conditions are obtained.

The invention discloses a sound absorber based on an Archimedes spiral curled acoustic metamaterial and a preparation method, the sound absorber comprises a sound absorption metamaterial cell element, a sound absorption channel is formed in the sound absorption metamaterial cell element, the sound absorption channel vertically penetrates through the sound absorption metamaterial cell element in the z-axis direction, the sound absorption channel is a spiral channel on the xy two-dimensional section, and the spiral channel is a spiral channel. One end of the spiral channel is opened in the side face of the sound absorption metamaterial cell element, the other end of the spiral channel is a blind end located in the center of the sound absorption metamaterial cell element, and the spiral channel is composed of two Archimedes spiral curves. According to the invention, a brand new sound absorption mechanism is adopted, the problems of strong dispersion and narrow bandwidth which are difficult to solve by a conventional resonance type structure are solved, and effective sound absorption (more than 0.5) of a broadband frequency band (2000Hz) can be realized in a range of 0-6000Hz.

The invention discloses a generating device capable of generating an ultra-flat broadband micro comb. The generating device comprises a pump pulse generating module, a micro comb generating module and a micro comb generating module, the pumping pulse compression module is connected with the pumping pulse generation module; the high-Q-value microcavity module is connected with the pumping pulse compression module; and the micro comb detection and feedback module is respectively connected with the high-Q-value micro-cavity module and the pump pulse generation module, and is used for monitoring the output spectrum and power change of the high-Q-value micro-cavity module and adjusting the output wavelength of the picosecond pulse light according to the output spectrum and power change so as to stabilize the ultra-flat broadband micro comb. By arranging the high-Q-value micro-cavity, the spectral bandwidth of the micro-comb can be effectively expanded, and the ultra-flat broadband micro-comb is output; meanwhile, the defects that the hyperbolic secant single soliton micro-comb is poor in flatness and narrow in bandwidth are overcome, and the micro-comb has obvious advantages in the application field with high requirements for the flatness and the spectral bandwidth at the same time.

The invention discloses a narrowband-broadband intelligent switching method of a radar, and belongs to the field of radar signal processing. Single radar wide-narrow band function integration is achieved through resource multiplexing, self-adaptive triggering and dynamic parameter configuration, detection tracking in a default narrow band mode is achieved, switching is triggered based on manual instructions and double thresholds, hardware such as a common antenna and a T / R assembly is reconstructed through time division multiplexing and software parameters, the signal synchronization time is shortened, and the target tracking response delay time is shortened; double-radar collaborative design is not needed, and the design workload is reduced. According to the invention, double radars are combined into a single radar, the hardware cost is greatly reduced, and the method is suitable for unmanned aerial vehicle-mounted, vehicle-mounted and other space-limited scenes and military reconnaissance, civil security and protection and other tasks.

The invention relates to the field of microelectronic devices, in particular to a bulk acoustic wave resonator with a double-layer piezoelectric film structure, a preparation method and a filter, the bulk acoustic wave resonator comprises a cap wafer, and a dry film, a passivation layer, a silicon oxide layer, a high-resistance silicon wafer and RDL metal are sequentially arranged on the cap wafer; the dry film and the cap wafer form a dry film cavity, the passivation layer located above the dry film cavity extends into the dry film cavity, and a top electrode, a first piezoelectric film, a middle electrode, a second piezoelectric film and a bottom electrode are sequentially arranged on the passivation layer; the top electrode and the bottom electrode are used as first ports of the resonator; and the middle electrode is a second port. According to the resonator, the excitation mode of the resonator is changed through cooperation of the two layers of piezoelectric films with the same polarization direction and the intermediate electrode, a high-order resonance mode is jointly excited, meanwhile, a high electromechanical coupling coefficient is kept, and a wide fractional bandwidth is achieved at high frequency through the relatively thick piezoelectric films; the problems that a high-frequency resonator is weak in power bearing capacity, narrow in bandwidth, low in quality factor and poor in stability are solved.

The utility model relates to a narrow-bandwidth multispectral camera, which is provided with a camera main body (10), and the camera main body (10) sequentially comprises a camera mainboard (1), a camera CMOS (complementary metal oxide semiconductor) assembly (2), a camera lens (3) and a filter (4) in the direction of an optical axis (P).

The invention provides a sub-wavelength structure unit and a preparation method thereof, a reflective array and a broadband planar film antenna, and the sub-wavelength structure unit comprises a sub-wavelength structure, a metal reflective layer, a first film and a second film. The sub-wavelength structure comprises at least two types of single resonant structures; the at least two types of single resonance structures are arranged on the first thin film; the metal reflecting layer is arranged on the second thin film; a spacing layer is arranged between the first film and the second film; and the phase and dispersion characteristics of the sub-wavelength structure unit in the first resonance area and / or the second resonance area are determined by setting parameters of the single resonance structure. According to the invention, the sub-wavelength structure comprises multiple types of single-resonant structures for forming different multi-resonant sub-wavelength structures, so that the problem of narrow bandwidth of a single-layer film antenna formed by the sub-wavelength structure unit can be solved.

A method of transferring data via an adaptive bit rate is described. The method includes, (i) in conjunction with capturing video data at the glasses and in response to receiving a request from the user of the glasses to stream the video data at the first device, receiving data used to assess a data transmission characteristic of the first narrow bandwidth communication channel, (ii) in accordance with a determination that the data transmission characteristic satisfies a first threshold, causing the video data to be sent at a first bitrate, (iii) in conjunction with capturing additional video data at the glasses, receiving new data used to assess a new data transmission characteristic of the first narrow bandwidth communication channel, and (iv) in accordance with a determination that the new data transmission characteristic satisfies a second threshold, causing the additional video data to be sent at a second bitrate.

The invention provides a drainage network monitoring system. The system comprises a sensing module for detecting one or more conditions at a location in the drainage network; a processing module for processing data received from the sensing module; a wireless communications module for communicating the processed data substantially in real-time to one or more wireless devices including a wireless notification device configured to issue notification information to users, wherein the wireless communications module utilizes a narrow bandwidth, low power wireless communications protocol to communicate processed data to the wireless notification device, and wherein the sensing module has a standalone power supply.

The invention provides a broadband filtering device and a multi-system access platform, and relates to the technical field of multi-system access platforms, and the broadband filtering device comprises a dielectric substrate; the resonator is arranged on the surface of the dielectric substrate; and the plurality of input units are wound on the resonator, each input unit comprises a first coupling line, a second coupling line and an input piece which are arranged on the surface of the dielectric substrate, the first coupling line and the second coupling line are connected with the input piece, the first coupling line and the second coupling line are coupled with the resonator, and the input piece is used for inputting an electric signal. According to the broadband filtering device and the multi-system access platform provided by the invention, the problem that the bandwidth is relatively narrow when a filtering device works in the prior art is solved.

The invention discloses an ultra-large octave antenna based on an organic photoconductive material, and belongs to the field of metamaterials and antennas. Comprising an organic photoconductor film electromagnetic surface and a digital light processing module capable of projecting different patterns on the surface of the organic photoconductor film electromagnetic surface, the organic photoconductor film electromagnetic surface can change conductivity distribution through light control, and the digital light processing module can dynamically adjust the size and shape of the patterns projected on the organic photoconductor film electromagnetic surface. Therefore, a reconfigurable antenna array is generated, and cross-multi-octave ultra-wideband electromagnetic wave signal receiving and transmitting are realized. The electromagnetic surface of the organic photoconductor film sequentially comprises a photoconductive material layer, a first light-transmitting glass layer, an indium tin oxide microstrip line feed layer, a second light-transmitting glass layer and a substrate indium tin oxide layer according to a lamination sequence. According to the invention, the problems of narrow bandwidth, slow response and high cost of a traditional reconfigurable antenna are solved.

The invention discloses a multispectral compatible camouflage and radiant heat management device and a multispectral camouflage system based on the same, relates to the field of multispectral camouflage materials and heat management, and aims to solve the problems of poor spectrum compatibility, narrow bandwidth, insufficient heat management and high angle sensitivity in the prior art. A phase change material layer is arranged on the metal substrate layer, and a phase regulation and control layer of a chessboard structure is arranged on the phase change material layer. According to the invention, the radar scattering cross section is large, the specular reflectance is very low, the performance can still be maintained in the incidence angle range of 0-30 degrees, the reflectance is not sensitive to the incidence angle and the polarization state, laser stealth, radar stealth and infrared camouflage can be realized, the spectrum compatibility is good, the bandwidth is wide, dynamic heat dissipation in a non-window can be realized, and the performance is stable. And the heat management effect is achieved.

The invention discloses an optimization design method of a reflective broadband achromatic focusing elastic metasurface, and belongs to the field of vibration and noise control. Aiming at the problems of narrow bandwidth, serious dispersion and the like of the existing focusing elastic metasurface, the invention provides an optimal design method of a reflective broadband achromatic elastic metasurface for realizing elastic longitudinal wave focusing by combining a variable density method based on a wave control principle. According to the method, a calculation model of a metasurface unit is established, a mode of efficiently and accurately calculating a reflection coefficient R of the metasurface unit based on a transfer matrix method is established, and a topological optimization formula for designing and generating the broadband achromatic focusing elastic metasurface unit is constructed based on a real part and an imaginary part of the reflection coefficient R. According to the method, manual participation is not needed, customization according to needs can be achieved, the designed metasurface unit has high efficiency and precision in a broadband, and design of the broadband achromatic elastic metasurface is achieved. The invention is especially suitable for the engineering fields of energy acquisition, wave sensing, communication, nondestructive testing and the like.

The invention discloses a bent channel-Helmholtz composite low-frequency broadband sound absorber and a design method thereof. The sound absorber is formed by connecting a plurality of bent channel metamaterial sound absorption units around a Helmholtz resonator unit in parallel in a coupling mode. By controlling the impedance of the Helmholtz neck and the impedance of the bending channel, each unit is in an under-loss state, and then the overall critical coupling is realized by utilizing the area coupling effect, so that the sound absorber has the sound absorption coefficient of more than or equal to 0.5 in the frequency band of 267-382Hz under the thickness of 35mm. According to the sound absorber, broadband efficient sound absorption is achieved through impedance coupling of the Helmholtz resonators and the bent channels, the problems that a traditional structure is narrow in frequency band, difficult to regulate and control and the like are solved, and theoretical and technical supports are provided for low-frequency noise control.

The invention relates to the technical field of audio noise reduction, and discloses an audio noise reduction method and system based on Polar code transmission, and the method comprises the steps: firstly obtaining an original audio signal, extracting an audio feature vector of the original audio signal, carrying out the suppression of a noise component in a feature domain, and obtaining an audio feature vector sequence after noise reduction; and feature coding and quantization are carried out on the feature sequence, and the feature sequence is converted into a bit stream with a compact structure so as to adapt to the narrow bandwidth and efficient transmission requirements of a wireless channel. In the channel coding stage, the high error correction capability and the polarization characteristic of the Polar code are fully utilized, the characteristic bit stream is effectively coded, and the anti-interference performance and the transmission robustness of the audio data in the severe wireless environment are greatly improved. And finally, mapping the bit stream after Polar coding into a modulation symbol, completing conversion to an analog radio frequency signal, and realizing high-quality wireless noise reduction transmission of an audio signal. Therefore, not only is the audio transmission quality improved, but also the reliability of data transmission is ensured.

The application discloses a terahertz biological tissue imaging system and method based on a metasurface antenna. The terahertz biological tissue imaging system comprises a terahertz signal generator, an intelligent system control device, a terahertz signal transmitter and a data acquisition module. The terahertz signal generator is used for generating an ultra-wideband terahertz wave signal. The intelligent system control device controls the terahertz signal generator to continuously generate the ultra-wideband terahertz wave signal. The terahertz signal transmitter is used for transmitting the ultra-wideband terahertz wave signal after programmable modulation to a biological tissue organ. The terahertz signal receiver is used for receiving terahertz biological signals scattered inside and around the biological tissue organ, and modulating the received terahertz biological signals. The data acquisition module is used for acquiring the terahertz biological signals. The intelligent sensing signal processing module is used for processing the terahertz biological signals to obtain a terahertz image of the biological tissue organ. The application solves the problems of narrow bandwidth and low gain in the corresponding technology.

To suppress the surge voltage of the first surge voltage caused by square waves and the second surge voltage caused by harmonic frequency components, to broaden the frequency characteristics of the output of the switching amplifier and to make the output frequency variable.SOLUTION: A switching amplifier in push-pull configuration with narrow bandwidth filter on the output side comprises a partial resonance circuit to suppress the first surge voltage caused by square waves and a LCR series resonator to suppress the second surge voltage caused by harmonic frequency components, and the waveform shape of the drain-source voltage Vds of the switching element is a trapezoidal waveform.SELECTED DRAWING: Figure 1

The invention discloses an angle-adjustable narrow-band heat radiator based on corner hyperbolic phonon polaritons. The heat radiator sequentially comprises a metal layer, a natural biaxial hyperbolic medium, a vacuum / air spacing layer and a one-dimensional medium grating. According to the angle-adjustable heat radiator, the biaxial hyperbolic medium and the gold layer are twisted as a whole, and the included angle between the radiating surface and the plane where the crystal axis of the natural biaxial hyperbolic medium is located is changed, so that the heat radiation direction is changed. The radiator can be produced on a large scale at low cost by utilizing processes such as nano photoetching and deposition. The narrow-band directional thermal radiation device obtained through the nano manufacturing technology is stable and reliable in performance, can generate thermal radiation with narrow bandwidth and small radiation angle, has the characteristics of adjustable direction, flexibility, convenience and the like, and is expected to be applied to the fields of directional heat dissipation, thermal camouflage and the like.

The application discloses a kind of communication link establishment initial stage security authentication encryption method, device and storage medium, the present application is limited to narrow bandwidth for end-to-end wireless communication link establishment, cannot apply conventional encryption preparation, it is difficult to guarantee that preset symmetric key is added after planning, abandon password protection is also prone to be maliciously controlled and so on Problem, an authentication encryption adaptive method based on pre-stored and diffusion key is proposed, by making full use of the key storage space of end device pre-stored key, supplemented by the diffusion transmission of new key with the process of link establishment, combined with the two modes of offline preset loading when opening and automatic online interaction after new communication terminal joins interworking, under the premise of no manual participation, maximum reduction to the occupation of link establishment narrow band, the security of information transmission is greatly improved, so as to improve user experience.

The utility model relates to a dual-channel optical filter based on a three-rectangular cavity edge coupling waveguide. The dual-channel optical filter comprises a silicon substrate, a sapphire layer, a graphene nano-strip waveguide, a first graphene rectangular resonant cavity, a second graphene rectangular resonant cavity and a third graphene rectangular resonant cavity, the sapphire layer is arranged above the silicon substrate; a graphene nano-strip waveguide, a first graphene rectangular resonant cavity, a second graphene rectangular resonant cavity and a third graphene rectangular resonant cavity are arranged on the upper surface of the sapphire layer; the first graphene rectangular resonant cavity and the third graphene rectangular resonant cavity are connected in series and arranged on one side of the graphene nano-strip waveguide, and the second graphene rectangular resonant cavity is arranged on the other side of the graphene nano-strip waveguide. According to the utility model, the problems of narrow bandwidth and poor filtering effect of an optical filter with a graphene structure are solved; the dual-channel optical filter which is small in size, wide in bandwidth, excellent in filtering effect, dynamically tunable and easy to integrate is realized in an infrared band.

The invention belongs to the technical field of communication, and particularly relates to a resource data sensing method and device and communication equipment, and the resource data sensing method comprises the steps that a sensing node collects multi-dimensional environment parameters and generates environment feature vectors, and a current interference type is recognized based on an interference classification model; according to the identified interference type, selecting an anti-interference algorithm combination corresponding to the first order from an anti-interference strategy library; adjusting a sensing parameter based on a dynamic parameter in the environment feature vector, and collecting and preprocessing target resource data to obtain noise-reduced resource data; evaluating the confidence coefficient of the denoised resource data, and if the confidence coefficient reaches the standard, outputting the resource data; if the confidence degree does not reach the standard, strategy iteration is triggered until resource data with the confidence degree reaching the standard are output, the method can adapt to diversified interference of narrow bands, wide bands and the like, matching of interference types and anti-interference strategies is achieved, interference is restrained to the maximum extent, the data distortion rate in the complex environment is reduced, and high-reliability data support is provided for resource scheduling.