57 results about "Power bandwidth" patented technology

The invention belongs to the field of structural health monitoring and mainly relates to a large-damping engineering structure modal parameter identification method. Cross-correlation function responded by structure vibration under random excitation is converted into a frequency domain, a real part or a virtual part of available frequency domain data are subjected to independent component analysis to acquire modal vibration model and modal response, rough modal frequency and damping ratio of modal responses of each order are calculated by adopting fast Fourier transform and a half-power bandwidth method, the rough modal frequency and the damping ratio are taken as initial values for fitting modal response curves to have the modal responses of each order fitted by adopting a least squares iterative estimation, and accurate values of the modal frequency of the each order and the damping ratio can be finally acquired. By the arrangement, independence assumption in independent component analysis of the processed data can be met, and the modal parameters with the large-damping structure can be accurately identified.

The present invention achieves technical advantages as an operational amplifier (30) having both a high slew rate and a full power bandwidth with low distortion by providing resistors (R6, R7, R9, R10) in place of active loads coupled to a differential pair (Q22, Q25, and Q23, Q24) of transistors in a folded cascode input stage (34). By utilizing passive resistors instead of active loads, no saturation occurs during high slew rate signals. The present invention achieves technical advantages of higher slew rate and lower noise without sacrificing power consumption.

The invention belongs to the technical field of energy capture, and particularly discloses a static threshold eliminating and dynamic threshold eliminating combined type voltage-doubler rectifier. According to the voltage-doubler rectifier, the static threshold eliminating technology and the dynamic threshold eliminating technology are combined, the equivalent threshold of a rectifier tube is changed through direct current bias so as to increase the positive-direction breakover current of the rectifier tube, and the rectifier tube is switched off with anti-phase radio-frequency signals so as to reduce the reverse leakage current of the rectifier tube. According to the voltage-doubler rectifier, high-efficiency power conversion under ultralow radio-frequency power input can be realized, good impedance matching within the bandwidth of wide input power can be realized, and then energy transmission efficiency within a wide power band is improved. When the voltage-doubler rectifier is applied to the fields such as radio frequency identification (RFID), label reading and writing sensitivity can be improved greatly, and then system sensitivity is improved.

The invention discloses a power allocation algorithm in a multi-beam satellite communication system. The power allocation algorithm comprises the following steps: at first, creating a downlink capacity model of the multi-beam satellite communication system for a user terminal according to a power bandwidth balancing principle in the multi-beam satellite communication system; then, creating a constrained optimization problem model for the power allocation problem; and finally, solving through the Lagrangian duality theory and a subgradient algorithm. The power allocation algorithm provided by the invention has excellence on the aspects of total capacity of the system and the total refusal amount of two-order services, good system performance can be obtained, and valuable power resources can be effectively utilized.

The invention relates to an adjacent channel interference elimination device and a method thereof for transmitting television signals, wherein the adjacent channel interference elimination device comprises a power detection unit, an interference elimination unit, a frequency shifter and a filter, wherein the power detection unit is used for detecting power of the television signals and judging whether adjacent channel signals cause strong adjacent channel interference on useful signals or not; the interference elimination unit comprises a frequency shifter and a filter; the frequency shifter is used for shifting the frequency of the television signals according to the power bandwidth of the filter when the power detection unit detects the adjacent channel signals which cause strong adjacent channel interference and for moving the adjacent channel signals which cause strong adjacent channel interference in the television signals to a stop band position beyond the power bandwidth of the filter; and the filter is used for filtering the adjacent channel signals at the stop band position according to frequency shifting results. The adjacent channel interference elimination device and the method thereof provided by the invention can eliminate the adjacent channel interference effectively with simple structure and lower computation complexity, and therefore, a receiver can obtain good-quality television signals.

The present invention achieves technical advantages as an operational amplifier (30) having both a high slew rate and a full power bandwidth with low distortion by providing resistors (R6, R7, R9, R10) in place of active loads coupled to a differential pair (Q22, Q25, and Q23, Q24) of transistors in a folded cascode input stage (34). By utilizing passive resistors instead of active loads, no saturation occurs during high slew rate signals. The present invention achieves technical advantages of higher slew rate and lower noise without sacrificing power consumption.

The invention relates to a metamaterial antenna which comprises a vibrator, a metamaterial film layer and a reflector, wherein the vibrator is used for generating electromagnetic waves; the metamaterial film layer is used for converging the electromagnetic waves generated by the vibrator and outwards radiating the electromagnetic waves and is also used for converting spherical electromagnetic waves generated by the vibrator into planar electromagnetic waves, and comprises a plurality of metamaterial sheet layers; and the reflector is used for reflecting partial electromagnetic waves generatedby the vibrator to the metamaterial film layer, is a cover-free cavity and forms a closed cavity together with the metamaterial film layer, and the vibrator is arranged in the reflector. Through changing the refractive index distribution condition inside the metamaterial film layer, the invention ensures that a half-power bandwidth of an antenna far field is reduced, further propagating distance of the antenna is increased, and front-to-back ratio of the antenna is increased.

The invention relates to a radio frequency identification reader-writer antenna linear array for emitting and receiving a radio signal, in particular a beam-formed ultrahigh frequency radio frequency identification reader-writer antenna linear array. A radiation patch substrate and a feed network substrate are in parallel symmetric connection through a support column, and an air layer is formed between the radiation patch substrate and the feed network substrate; radiation units of the radiation patch substrate are square copper sheets; the lower surface of the feed network substrate is a one-to-five unequal power distributor, an input port is connected with a 50Ohm SMA adaptor; the upper surface of the feed network substrate is a ground surface and five dumbbell shaped grooves are etched on the upper surface, the five dumbbell shaped grooves are respectively corresponding to radiation units on the above radiation patch substrate. The directivity of the wave beam is realized through the adoption of the beam-formed ultrahigh frequency radio frequency identification reader-writer antenna linear array provided by the invention; the antenna linear array has a downward inclination angle at 30 DEG and a half-power bandwidth at 25 DEG, and can be used for performing identification aiming at labels in a certain specific region, and the labels out of the region cannot be identified.

The invention discloses a compressed sampling method for a multiband signal, relates to the field of multiband signal sampling, and solves the problem of limitation of a signal frequency application range of a multi-coset compressed sampling system due to low full-power bandwidth of an analog front end of the existing multi-coset compressed sampling system. The method adopts p channels to sample a signal x(t), and a specific sampling method of an ith channel comprises the following steps of carrying out frequency mixing on the multiband signal x(t) and a signal Mi(t) to obtain a signal (FORMULA) after frequency mixing; filtering the signal (FORMULA) by adopting an ideal low-pass filter h(t) with the cut-off frequency of f0 / 2; sampling under the frequency fs=f0 by adopting an analog-digital converter in order to obtain a sampling sequence yi[n]; reconstructing by a reconstruction algorithm through p sampling sequences y[n]=(y1[n] to yi[n] to yp[n]) in order to obtain sequences d[n]=(dL0[n] to dL0[n])<T>, and thereby completing compressed sampling for multiband signal. The compressed sampling method is suitable for sampling the multiband signal with the unknown carrier frequency.

A joint distribution method of a multi-channel power bandwidth in a cognitive radio network belongs to the field of radio technology. The method comprises: 1, a secondary user transmitter end sets a transmission power limit and a bandwidth constraint; 2, the secondary user transmitter end obtains channel state information in a channel state measurement module through signaling interaction with the secondary user receiver end and estimation of historical data; 3, the secondary user transmitter end sets a soft interference constraint; 4, the secondary user transmitter end carries out joint distribution of power and bandwidth to maximize the average transmission rate in a power bandwidth decision module; 5, the secondary user transmitter end uses a parsing method to solve the optimal solution of the fixed Lagrange multiplier; and 6, whether the communication between the secondary user transmitter end and the secondary user receiver end is completed is judged; if the communication is not completed, the method returns to the step 2 and continues channel state information detection of a next relevant time; or if the communication is completed, the traversal capacity is calculated. The invention has a low complexity.

The invention discloses a power modeling method and a power managing method for calculation in internal storage. The power modeling method comprises the following steps: establishing a BP model, and adopting each power bandwidth BP to represent a relationship between bandwidth and power for calculating PIM in internal storage; the power managing method comprises the following steps: power monitoring sub task limit PAST, processing unit acceleration PUB and power sprint PS; when power supply exceeds power needs, adopting PAST to manage power consumption in PIM; adopting a PUB method while needing to adopt a dynamic regulating power mode; while short-time power overload is required, adopting a PS method to improve a power upper limit value of a power arbiter; and realizing power management for calculation in internal memory. Power obtained by adopting the BP model is consistent with practically measured power, the PAST method can successfully limit power of the PIM, and the PUB can successfully improve performances of a chip; and meanwhile, the PAST method, the PUB method and the PS method can be adopted to generate a more effective energy system, and a power management scheme is reasonably configured, so that performances of PIM are further improved.

The invention provides a power grid-friendly type wind power plant energy storage capacity optimal configuration method. Fluctuation requirements of a power grid on the grid-connected power of the wind power plant for 1min and 10min are equivalent to slope signals with a fluctuation limit value as the limit in a corresponding time; a preliminary grid-connected power bandwidth meeting the grid-connected requirement is obtained, the output power of the wind power plant is decomposed by using wavelet packet decomposition according to the bandwidth to obtain preliminary grid-connected power, an optimal space range is further obtained according to the preliminary grid-connected power and the output power of the wind power plant, optimization is carried out by using a particle swarm algorithm according to a target function, the final grid-connected power is obtained, and energy storage equipment is configured. The method provided by the invention can well solve the problem of over-configuration of the energy storage equipment of the wind power plant.

The invention discloses a signal analyzing device used for synchronously separating signals and noise and an analyzing method thereof. The input ends of the first filtering branch and a second filtering branch are respectively connected with an AD converter. The AD converter inputs medium-frequency analog signals. The output ends of the first filtering branch and the second filtering branch are respectively connected with a subtractor used for achieving subtraction operations of two paths of signals. The subtractor is connected to a signal index memory through a comparator. The comparator is used for comparing the difference setting thresholds of the two paths of digital signals and outputting the index value of the digital signal on the point to the signal index memory for storage. The noise power bandwidth characteristics and the band limited signal characteristics are fully researched. The two filtering branches are adopted to filter signals synchronously. Synchronous separation of signals and noise is achieved.

The invention relates to a device and a method for detecting corrosion of a metal structure under a protective layer through a microwave resonance cavity. The device comprises an automatic network analyzer and further comprises a frequency scanning source, an isolator, a distributor and a first coupling probe arranged in a resonance cavity body which are connected with the automatic network analyzer in turn, wherein a second coupling probe arranged in the resonance cavity body is connected with an attenuator, the distributor, the isolator, a signal microprocessor circuit and the automatic network analyzer in turn through a coaxial cable; a plurality of corrosion degree indicator lamps are connected with the automatic network analyzer; and an opening of the resonance cavity body is formed at the lower end of the resonance cavity body. The method comprises the following steps: detecting amplitude-frequency characteristics of the resonance cavity and a detected object at different corrosion degrees, and obtaining resonant frequency, peak power and half-power bandwidth, thereby obtaining the corrosion degree of the metal structure under the protective layer. The device has the advantages of simple structure, high speed and convenience in detection, high reliability, and capability of realizing the detection for the corrosion degrees of the metal structures under the protective layers in different thickness.

A multi-zone digital-to-analog device is provided with a digital-to-analog (D / A) stage having an input to accept a digital input signal with a data bandwidth of M Hertz (Hz), a clock input to accept a clock signal with a clock frequency of P Hz, and an output to supply an analog value having a bandwidth of M Hz. An upsampling stage has an input to accept the analog value and a clock input to accept the clock signal. The upsampling stage has a device bandwidth of L Hz to supply an analog output signal with a full power bandwidth of K Hz, where (P / 2)=M and M<K<L. The upsampling stage supplies analog output signal images in a plurality of Nyquist zones. In one aspect, the D / A stage supplies N deinterleaved analog values having a combined bandwidth of M Hz, where N×(P / 2)=M.

The invention discloses an ultra-wideband gradient temperature compensation distributed microwave power amplification chip, and belongs to the field of microwave radio frequency chips. The power amplifier comprises a cascode amplification structure, an input artificial transmission line and an output artificial transmission line, the cascode amplification structure comprises a plurality of stages of cascode amplification networks with the same structure, and the input end of each stage of cascode amplification network is connected with the input artificial transmission line. The output end of each stage of cascode amplification network is connected with the output artificial transmission line, and each stage of cascode amplification network comprises a cascode amplification unit, an RC stabilization unit, a first grid voltage temperature compensation voltage division unit, a grid-to-ground unit, a second grid voltage temperature compensation voltage division unit, a matching capacitor and a first bias resistor. The high-frequency gain and the power bandwidth are expanded through the transistors of which the sizes are reduced step by step and the independently matched artificial transmission lines, and the temperature compensation of the grid voltage of the transistors is realized by utilizing the resistance characteristics of different temperature coefficients.

A multi-zone digital-to-analog device is provided with a digital-to-analog (D / A) stage having an input to accept a digital input signal with a data bandwidth of M Hertz (Hz), a clock input to accept a clock signal with a clock frequency of P Hz, and an output to supply an analog value having a bandwidth of M Hz. An upsampling stage has an input to accept the analog value and a clock input to accept the clock signal. The upsampling stage has a device bandwidth of L Hz to supply an analog output signal with a full power bandwidth of K Hz, where (P / 2)=M and M<K<L. The upsampling stage supplies analog output signal images in a plurality of Nyquist zones. In one aspect, the D / A stage supplies N deinterleaved analog values having a combined bandwidth of M Hz, where N×(P / 2)=M.

The invention relates to a metamaterial antenna. The antenna comprises a vibrator, a first metamaterial thin-film layer, a second metamaterial thin-film layer and a reflector, wherein the vibrator is used for radiating electromagnetic waves; the first metamaterial thin-film layer is used for refracting, converging and externally propagating the electromagnetic waves radiated by the vibrator; the first metamaterial thin-film layer is connected with the reflector and forms a closed cavity with the reflector; the second metamaterial thin-film layer is arranged on the bottom layer in the reflector; and the vibrator is arranged on the second metamaterial thin-film layer and is connected with a peripheral signal transmitter by a feeder. The metamaterial antenna has the following beneficial effects: by arranging the second metamaterial thin-film layer in the reflector and arranging the first metamaterial thin-film layer at the opening of the reflector, the half-power bandwidth of the antenna is greatly reduced and the front-to-back ratio of the antenna is increased so that the directionality of the antenna is better and farther transmission of the antenna is promoted.

The embodiment of the invention provides an electrical length determination method of compensation wires and a Doherty power amplifier, and relates to the technical field of the communication. The Doherty power amplifier comprises a main power amplification circuit, a peak power amplification circuit, a first compensation wire and a second compensation wire; the main power amplification circuit iselectrically connected with the first compensation wire, the peak power amplification circuit is electrically connected with the second compensation wire, and the first compensation wire and the second compensation wire are electrically connected to form a compound point. Since the electrical length of each of the first compensation wire and the second compensation wire is provided through the electrical length determination method of the compensation wires, and is computed and acquired according to a power rollback point demand value determined based on a preset signal peak-to-average ratioand a peak power ratio, namely, the actual power rollback point of the Doherty power amplifier provided by the invention is determined according to actual demands, therefore, relatively high power under the power rollback condition can be guaranteed, and the normal work at the full power is guaranteed, and the Doherty power amplifier has relatively wide power bandwidth.

The invention discloses a metamaterial. The response of the metamaterial to electromagnetic waves is equal to the response of a convex mirror to electromagnetic waves, wherein the convex mirror is formed by the intersection of two spherical surfaces with a radius r. The metamaterial comprises a base material and multiple artificial microstructures, wherein the multiple artificial microstructures are periodically arranged on the surface of the base material. The refractive index distribution of the metamaterial meets a rule shown in the specification. Compared with the traditional lens, the metamaterial is smaller in volume and simpler in processing, and an electromagnetic wave which is emitted by a point source is larger in far-field maximum and smaller in half-power bandwidth after passing through the metamaterial.

The invention discloses a high-power intermodulation distortion detection device and method. The device comprises detection equipment and a detection loop, wherein a device to be detected is connected with the detection equipment through the detection loop; an RF source card and an any waveform generator (AWG) are arranged in the detection equipment; the detection loop comprises a power amplifier, first and second filters and an attenuator. The method comprises the following steps: emitting an I / Q (in-phase / quadrature) modulation signal by the AWG, emitting a carrier wave signal by the RF source card, and loading the I / Q modulation signal into the carrier wave signal to obtain a dual-tone signal for detecting intermodulation distortion. According to the high-power intermodulation distortion detection device and method, the purpose of forming the dual-tone signal by the RF source card can be achieved by emitting the carrier wave signal by only one RF source card, so that the use frequency of the RF source card is reduced and the production cost is reduced; further, the bandwidth and power of the dual-tone signal can be determined by the I / Q modulation signal emitted by the AWG, the dual-tone signal with the same power and relatively large bandwidth can be generated, and the dual-tone signal with relatively small bandwidth and different power also can be generated, so that relatively good operation selectivity is achieved.

The invention discloses a partial feedback microwave antenna system composed of metamaterial, a feedback source located below the metamaterial and a reflecting device, wherein the reflecting device is placed on a horizontal line in an inclined mode, the inclination angle between the reflecting device and the horizontal line is theta, the metamaterial is composed of metamaterial sheet layers from the first layer to the Nth layer and a reflecting plate tightly attached to the metamaterial sheet layer of the Nth layer, each layer of metamaterial sheet layer comprises a substrate and a plurality of artificial metal micro structures arranged on the substrate according to periods, electromagnetic waves radiated by the feedback source are reflected to the metamaterial by the reflecting device, and the metamaterial radiates the electromagnetic waves out in a plane wave mode. Due to the fact that the metamaterial is adopted for the partial feedback microwave antenna system to modulate the electromagnetic waves, the electromagnetic waves are made to be radiated out in the plane electromagnetic wave mode, and therefore overall gains of the antenna system are improved. Meanwhile, according to the microwave antenna system, the position of the feedback source, the position of the conical reflecting body, and the position of the metamaterial are reasonably arranged, and therefore the maximum valve of a far field of the microwave antenna system and the half-power bandwidth are very good in performance.

The invention relates to a device and a method for detecting corrosion of a metal structure under a protective layer through a microwave resonance cavity. The device comprises an automatic network analyzer and further comprises a frequency scanning source, an isolator, a distributor and a first coupling probe arranged in a resonance cavity body which are connected with the automatic network analyzer in turn, wherein a second coupling probe arranged in the resonance cavity body is connected with an attenuator, the distributor, the isolator, a signal microprocessor circuit and the automatic network analyzer in turn through a coaxial cable; a plurality of corrosion degree indicator lamps are connected with the automatic network analyzer; and an opening of the resonance cavity body is formed at the lower end of the resonance cavity body. The method comprises the following steps: detecting amplitude-frequency characteristics of the resonance cavity and a detected object at different corrosion degrees, and obtaining resonant frequency, peak power and half-power bandwidth, thereby obtaining the corrosion degree of the metal structure under the protective layer. The device has the advantages of simple structure, high speed and convenience in detection, high reliability, and capability of realizing the detection for the corrosion degrees of the metal structures under the protective layers in different thickness.

The invention discloses an operational amplifier testing system. An operational amplifier serves as a core integrated component in the book of Simulation and Digital Circuit, a testing circuit and a testing method of parameters of the operational amplifier will greatly inspire students and help the students to deepen the understanding of electric foundation courses, however, multiple parameters ofthe operational amplifier are difficult to test, and definite and accurate experimental results are difficult to obtain. The operational amplifier testing system comprises an open-loop gain testing system, an offset voltage adjustment testing system, a slew rate testing system, a full-power bandwidth testing system, a unit gain bandwidth testing system and a gain bandwidth product testing systemof a same-phase amplifier. Compared with the prior art, the operational amplifier testing system has the advantages that the six parameters of the operational amplifier can be accurately detected; thedemand for performance of a needed detection instrument is low, and the experimental construction cost is saved; the operation amplifier testing system can be controlled through remote access.

The invention relates to a metamaterial antenna. The antenna comprises an oscillator for generating electromagnetic waves, and a metamaterial film layer for converging the electromagnetic waves generated by the oscillator and then radiating the electromagnetic waves outwards and also for converting spherical electromagnetic waves generated by the oscillator into plane electromagnetic waves; the antenna also comprises a reflecting body for reflecting part of the electromagnetic waves generated by the oscillator into the metamaterial film layer, and two conductors for reflecting part of the electromagnetic waves at the connection part between the reflecting body and the metamaterial film layer, wherein the oscillator is located in the reflecting body; and the reflecting body, the two conductors and the metamaterial film layer are connected successively, and collectively constitute a closed cavity. The metamaterial antenna provided by the invention has the beneficial effects that by arranging the vertical conductors at an opening of the reflecting body and arranging the metamaterial film layer on the conductors, the half-power bandwidth of the antenna is greatly reduced, the front-to-back ratio of the antenna is improved, so that the antenna directivity is better, and further-distance emission of the antenna is promoted.

The invention discloses a power bandwidth joint allocation method for target tracking of a networking radar, and the method comprises the following steps: tracking a target at a k moment through employing Kalman filtering, and obtaining the prediction information of a target state at a k+1 moment; acquiring an FIM determinant of target state estimation by using the state prediction information of the target at the k+1 moment so as to measure the tracking precision of the target; taking the determinant of the maximized FIM as a target function, and establishing a double-variable optimization problem containing two variables of power and bandwidth; describing a bivariate optimization problem as a cooperative game optimization model for maximizing alliance benefits; and solving the cooperative game optimization model by using a Shapley value algorithm in combination with a cyclic minimization algorithm to obtain an optimal power and bandwidth allocation scheme at the k+1 moment. According to the invention, power bandwidth joint allocation under the target tracking background is realized, the target tracking precision is improved, the problem of low resource utilization rate under the condition that multiple resources are limited is solved, and the target tracking performance of the system is further improved.

The invention discloses a microwave antenna system which comprises metamaterial, a feed source and a cone, wherein an open hole is formed in the middle of the metamaterial, the feed source is installed in the center of the open hole, and the cone and the feed source are installed coaxially. The metamaterial is composed of first to Nth metamaterial slice layers and a reflection plate which is tightly attached to the Nth metamaterial slice layer. Electromagnetic waves radiated by the feed source are reflected to the metamaterial through the conical surface of the cone, and the metamaterial radiates the electromagnetic waves in the form of plane waves. Each metamaterial slice layer comprises a substrate and a plurality of man-made metal microstructures which are periodically arranged on each substrate. According to the microwave antenna system, the metamaterial is adopted for modulating the electromagnetic waves so that the electromagnetic waves can be radiated in the form of the plane electromagnetic waves, and therefore overall gain of the microwave antenna system is improved. Meanwhile, as for the microwave antenna system, the position of the feed source, the position of the reflection cone and the position of the metamaterial are arranged reasonably, and therefore the far-field maximum value and the half-power bandwidth of the microwave antenna system are shown very well.

The invention discloses a high-power bandwidth filter which comprises a box body, an optical input module, a first optical output module and a second optical output module which are arranged on the box body, and a band-pass optical filter arranged in the box body, wherein the first side face of the band-pass optical filter is plated with a band-pass film, the second side face of the band-pass optical filter is plated with an antireflection film, the included angle between the optical input module and the band-pass optical filter is equal to the included angle between the second optical output module and the band-pass optical filter, and the first optical output module is located on the extension line of the optical input module. The band-pass optical filter is arranged on a connecting line between the optical input module and the first optical output module, and a band-pass film of the band-pass optical filter faces the optical input module. The embodiment of the invention can improve the bearing power of the bandwidth filter, is good in heat dissipation effect, and can be widely applied to the technical field of optical devices.