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188results about How to "Reduce phase error" patented technology

Clock and data recovery circuit having wide phase margin

InactiveUS20070047683A1Wide phase marginIncrease speedPulse automatic controlSynchronisation receiversSerial samplingPhase control
A clock and data recovery (CDR) circuit includes a sampler, a CDR loop and a phase interpolator. The sampler samples serial data in response to a recovery clock signal to generate a serial sampling pulse. The CDR loop transforms the serial sampling pulse into parallel data, generates a plurality of phase signals with a first speed based on the parallel data, and generates a phase control signal with a second speed higher than the first speed based on the plurality of phase signals. The phase interpolator generates the recovery clock signal by controlling a phase of a reference clock signal in response to the phase control signal. Therefore, the CDR circuit may recover data and a clock with a relatively high speed.
Owner:SAMSUNG ELECTRONICS CO LTD

Clock adjustment circuit and adjustment method for clock circuit

The invention provides a clock adjustment circuit and an adjustment method for a clock circuit. The clock adjustment circuit comprises a clock buffer amplifier, a phase discriminator and a duty cycle adjustment circuit, wherein the clock buffer amplifier is used for receiving an external differential clock signal, shaping the differential clock signal into a single-end square wave clock signal and outputting the single-end square wave clock signal; the phase discriminator is used for receiving the single-end square wave clock signal from the clock buffer amplifier and a feedback signal from the duty cycle adjustment circuit, comparing the phase of the single-end square wave clock signal with the phase of the feedback signal to acquire a phase difference, and outputting the phase difference; and the duty cycle adjustment circuit is used for adjusting the duty cycle of the feedback signal by using the phase difference to acquire an adjusted feedback signal. The differential signal is shaped into the single-end square wave clock signal, the single-end square wave clock signal is compared with the feedback signal to acquire the phase difference, and the duty cycle is adjusted according to the phase difference, so that the complexity of duty cycle adjustment and hardware implementation can be effectively reduced, phase errors and the ripple waves of control voltage can be reduced, and adjustment accuracy is improved.
Owner:XIDIAN UNIV

Phase and frequency detection circuits for data communication systems

In one embodiment, a phase-locked loop system in a receiver samples received incoming data using a first clock and a second clock that have the same frequency but are out of phase with each other. A first control signal generated by a phase detector is used to control a charge pump, whose output may be filtered to drive a VCO circuit generating the first and second clocks. A frequency detector generates a second control signal based at least on phase relationships between the incoming data and the first and second clocks. A qualifier circuit determines if the first control signal is valid or invalid based at least on the second control signal. If the first control signal is invalid, the qualifier circuit prevents the first control signal from being used to adjust the frequency of the first and second clocks.
Owner:REALTEK SEMICON CORP

Clock circuit capable of realizing stable duty ratio and phase calibration

ActiveCN102761319AReduce phase errorAvoid the effects of coupled noiseSingle output arrangementsSquare waveformEngineering
The invention discloses a clock circuit capable of realizing a stable duty ratio and phase calibration, which is used for adjusting the duty ratio and the phase of a clock signal. The clock circuit comprises a clock distribution network used for carrying out buffer output on the clock signal, a duty ratio correction module and a phase calibration module, wherein the duty ratio correction module is used for converting an input differential signal into a square signal with a fixed duty ratio and then outputting the square signal to the phase adjustment module; and the phase adjustment module is used for adjusting the phase of the input square signal by utilizing an in-phase clock signal and an antiphase clock signal which are fed back by the clock distribution network and generating and inputting a clock signal to the clock distribution network. By adopting the clock circuit, the purposes of stable duty ratio and phase calibration of the output clock signal are achieved.
Owner:BEIJING MXTRONICS CORP +1

An Imaging Method of Nonlinear Frequency Modulation Scaling for Synthetic Aperture Radar

The invention belongs to an imaging method for nonlinear frequency modulation label change in the synthetic aperture radar imaging technology, which comprises the steps of two-dimensional frequency domain unfolding, filtering processing, nonlinear frequency modulation label change, distance compression, distance migration correction, rest phase compensation and position compression. In the method of the invention, the characteristics of orthogonality and minimum square error of the Legendre polynomials are utilized for carrying out three-order unfolding on the two-dimensional frequency domain signals of the obtained echo signals according to the Legendre orthogonality polynomials, and then, the focusing imaging on targets is realized through carrying out filtering processing and the like on three-order phase items in echo signal two-dimensional frequency domain expression. When the method of the invention is adopted, the maximum phase error under the same condition is less than 0.2 percent of the maximum phase error in the prior art, so the assurance is provided for the high-precision imaging under the large-inclination view angle condition. Therefore, the method of the invention has the characteristics that the phase error in the imaging process can be effectively reduced, the imaging processing of the large-inclination view angle is realized, in addition, the imaging effect is good, the imaging processing efficiency and the precision are high, and the like.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA

Quadrature frequency doubler with adjustable phase offset

The present invention provides an improved frequency doubling circuit, with adjustable phase offset. Briefly, rather than using the traditional equations cos (2ωt)=cos 2(ωt)−sin 2(ωt) and sin(2ωt)=2 sin(ωt)cos(ωt), the quadrature output signals are generated utilizing mixers, each having two input signals, separated in phase by the same offset. This minimizes the effects of the non-linearities introduced by the mixer, which therefore reduces amplitude mismatch between the quadrature signals. Also, the phase offset of the quadrature output signals can be tuned and calibrated using a phase shifting circuit. This phase shifting circuit realizes a tuning range of approximately 5° in programmable steps. This combination of circuits can be used to minimize the amplitude mismatch and phase errors, thereby reducing the amplitude of and interference caused by transmission of the image frequency to the receivers input.
Owner:EDGEWATER WIRELESS SYST

Bayesian iterative reweighted sparse autofocus array SAR imaging method

The invention discloses a Bayesian iterative reweighted sparse autofocus array synthetic aperture radar (SAR) imaging method. The Bayesian iterative reweighted sparse autofocus array SAR imaging method aims at the influence of phase errors existing in array SAR echo signals on imaging results. Based on a traditional sparse autofocus Bayesian recovery via iterative minimum (SAFBRIM) algorithm, a linear measurement matrix of scattering coefficients in the array SAR original echo signals and an observation scene target space is established, norm items in a cost function in the algorithm are subjected to iterative adaptive reweighted processing, pulse compression and equidistant surface division are carried out on a distance direction, and then each equidistant two-dimensional surface is estimated. According to the Bayesian iterative reweighted sparse autofocus array synthetic aperture radar (SAR) imaging method, different weighting coefficients are given to each norm item, and then imagesare reconstructed, so that higher-quality array SAR imaging results can be obtained. The Bayesian iterative reweighted sparse autofocus array synthetic aperture radar (SAR) imaging method has the advantages of high reconstruction precision and effective reduction of phase errors, and can be applied to the fields such as array synthetic aperture radar imaging.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA

Geo-synchronous orbit synthetic aperture radar (GEO SAR) frequency modulation changeable standard imaging method under curve track model

The invention discloses a geo-synchronous orbit synthetic aperture radar (GEO SAR) frequency modulation changeable standard (CS) imaging method under a curve track model. The method comprises the following steps of: establishing an oblique-distance and high-order expression under the GEO SAR curve track model; deducing a two-dimensional spectrum expression of an echo signal; performing triple Taylor expansion of a distance frequency on the two-dimensional spectrum expression; compensating a triple phase item of the distance frequency in a two-dimensional frequency domain; calculating a distance migration curve in a distance-Doppler domain and multiplying the distance migration curve by a constructed CS phase function; deducing a distance compensation function to finish distance focusing and distance migration correction; and performing direction compression and direction residual phase correction to finish direction focusing. By the method, the spatial-variant properties of the distance migration can be compensated, a wider imaging plotting bandwidth can be obtained and full-aperture high-resolution imaging can be realized. All types of operation in the method are finished throughfast Fourier transform and phase dot product; furthermore, the efficiency is higher and the method is suitable for engineering implementation.
Owner:XIDIAN UNIV

Method for optimizing SAR (Specific Absorption Rate) extended scene imaging on double-base forward-looking high-mobility platform

The invention discloses a method for optimizing SAR (Specific Absorption Rate) extended scene imaging on a double-base forward-looking high-mobility platform. The method comprises the following main steps: obtaining an SAR time domain echo signal of a point target at first so as to obtain an echo signal and a range history after the linear moving amount is corrected, and then, carrying out azimuth FFT (Fast Fourier Transform) of the echo signal after the linear moving amount is corrected so as to obtain a two-dimensional frequency spectrum of the time domain echo signal; and carrying out high-order approximation of the range history after the linear moving amount is corrected, carrying out Taylor series development in the range direction after obtaining the phase term of the high-precision two-dimensional frequency spectrum after the linear moving amount is corrected, eliminating the phase space-variant property of the phase term of the high-precision two-dimensional frequency spectrum by adopting high-order polynomial fitting, carrying out range domain IFFT (Inverse Fast Fourier Transform) after obtaining a phase compensation signal having good focus in the range domain through a matching filter designed through the two-dimensional frequency domain, and then, obtaining focused SAR imaging through the matching filter designed in a range-Doppler domain.
Owner:XIDIAN UNIV

Optimization method based on traditional phase difference measurement and circuit

The invention, which belongs to the signal processing technology field, discloses an optimization method based on traditional phase difference measurement and a circuit. According to the method, two sinusoidal signals with different frequencies or a same frequencies pass through a signal collection circuit, an amplification circuit, and a comparison circuit as well as two paths of rectangular wave signals pass through an OR gate circuit so as to obtain a needed pulse signal; AD sampling is carried out so as to obtain a pulse width and a time difference of signal zero crossing, so that a phase difference is calculated. According to the invention, because a special circuit design is employed, phase drift generated by hardwares of a traditional zero cross detection circuit itself can be substantially changed, so that correlated subsequent processing of the phase difference on software becomes easier; therefore, the strong practicality is realized.
Owner:SHANGHAI HUAJIAN ELECTRICAL EQUIP

Temperature compensation system for real-time clock and method

The invention discloses a temperature compensation system for a real-time clock. The temperature compensation system for the real-time clock comprises a repairing regulating register, a compensation interval register, a low-phase error repairing regulating mechanism controller, a crystal oscillator and a frequency repairing regulating circuit, wherein the repairing regulating register is used for storing an increasing and reducing pulse flag bit F and a repairing regulating data M; the compensation interval register is used for storing a compensation interval time value T; the low-phase error repairing regulating mechanism controller connected with the repairing regulating register is used for outputting a repairing regulating value m of a present second clock within the compensation interval time value T by judging the second clock corresponding to the compensation under the present state according to the size of the repairing regulating data; the crystal oscillator is used for generating a clock frequency; and the frequency repairing regulating circuit connected with a clock generator and the low-phase error repairing regulating mechanism controller is used for performing a pulse increasing and reducing operation on the clock outputted by the crystal oscillator according to the increasing and reducing pulse flag bit F and finally outputting an accurate low-phase error 1Hz clock when the repairing regulating value m of the present second clock is received by the frequency repairing regulating circuit.
Owner:PERICOM TECH (SHANGHAI) CO LTD

Power transformer winding fault online monitoring device and diagnosis method

The invention relates to a power transformer winding fault online monitoring device and a diagnosis method, and belongs to the technical field of power transformer fault diagnosis. The power transformer winding fault online monitoring device is characterized in that the output end of a voltage sensor and the output end of a current sensor are connected to the input end of a synchronous signal sampling circuit, the output end of the synchronous signal sampling circuit and the output end of an ultrahigh frequency sensor are connected to the input end of a signal conditioning circuit, the output end of the signal conditioning circuit is connected to the input end of a DSP (Digital Signal Processor) through an A / D conversion circuit, the output end of the DSP is connected with a PC (Personal Computer) through a CPLD (Complex Programmable Logic Device), and the PC is connected with an alarm. The diagnosis method comprises the steps of acquiring ultrasonic signals at the wall of a transformer oil tank, and finally acquiring coordinates of partial discharge through signal conditioning and A / D conversion and through DSP denoising; acquiring voltage signals and current signals, processing the signals, building an online short-circuit reactance model, acquiring a short-circuit reactance value of each phase winding, comparing the acquired short-circuit reactance value with a corresponding historical fault-free short-circuit reactance value so as to acquire the short-circuit reactance change rate, judging a range, in which the change rate is located, of an upper limit threshold and a lower limit threshold, and judging the winding operating state.
Owner:STATE GRID LIAONING ELECTRIC POWER RES INST +2

Output phase-locked loop system of grid-connected converter and control method

The invention discloses an output phase-locked loop system of a grid-connected converter and a control method. The system comprises a Clark transform module for Clark transform of a three-phase voltage signal outputted by a grid-connected converter, a delay elimination module for carrying out delay elimination on two phases of voltages in an alpha-beta coordinate system, a Park transform module for Park transform of the two phases of voltages in the alpha-beta coordinate system after delay elimination according to an initial output phase, a PI regulator for PI adjustment on a q-axis signal, an integration module for integration processing on a grid voltage estimation value to obtain an initial output phase, an amplification module for amplification of a frequency adjustment error to obtain a phase compensation value, and a superimposition module for superimposition of the initial output phase and the phase compensation value to obtain a final output phase. With the output phase-locked loop system and the control method, the fundamental frequency and phase information of the output voltage of the grid-connected converter can be obtained accurately when the system voltage is not balanced or distorts.
Owner:STATE GRID SICHUAN ELECTRIC POWER CORP ELECTRIC POWER RES INST +1

Synchronous orbit SAR imaging method based on high-order polynomial range equation

The invention discloses a synchronous orbit SAR (Synthetic Aperture Radar) imaging method based on high-order polynomial range equation. The implementation process thereof is as follows: 1. establishing a synchronous orbit SAR high-order polynomial range equation; 2. solving a Cardan equation and deducing the precise analytical expression of a synchronous orbit SAR echo signal two-dimensional frequency spectrum; 3. structuring a two-dimensional frequency domain compensation function and finishing a scene centre point matching processing in the two-dimensional frequency domain; 4. performing arange IFFT (Inverse Fast Fourier Transform) processing on a result after finishing the centre point matching and transforming the result to a range-Doppler domain from the two-dimensional frequency domain; 5. structuring an error phase spatially variant with range and compensating for a range spatially variant phase in the range-Doppler domain; and 6. performing an azimuth IFFT processing to obtain a focused synchronous orbit SAR image. All the operations in the invention are finished by fast Fourier transform and phase dot product, and the method is high in efficiency and suitable for engineering implementation; and moreover, the two-dimensional frequency spectrum is a precise analytic solution capable of realizing full-aperture and high-resolution imaging.
Owner:XIDIAN UNIV

High-downdip electrically controlled base station antenna

The invention discloses a high-downdip electrically controlled base station antenna. The antenna comprises a reflection board, an array, a phase shift mechanism and an adjusting mechanism, wherein the array is arranged on one side of the reflection board and is provided with multiple dual-polarized vibrators; the phase shift mechanism and the adjusting mechanism are arranged on the other side of the reflection board; the phase shift mechanism is provided with a first shunt-feed strip-shaped wire and a first medium board; the first shunt-feed strip-shaped wire is connected with the dual-polarized vibrators, and is provided with a tap and multiple conduction bands reversely extending from the edge of the tap; the first medium board is simultaneously overlapped on at least part of the reversely extended conduction bands; and the adjusting mechanism is connected with the first medium board so as to drive the first medium board to move in the extension direction of the conduction bands. The antenna has the advantages that: the first shunt-feed strip-shaped wire is provided with multiple reversely extended conduction bands and the first medium board is simultaneously overlapped on the reversely extended conduction bands, so that the first medium board is matched with the reversely extended conduction bands to form multiple parallel-connection phase shift units, thus the feeding network layout is simplified, the feeding loss is reduced, the benefit is increased and the bandwidth is broadened.
Owner:东莞市晖速天线技术有限公司

Delay-locked loop circuits and method for generating transmission core clock signals

A delay-locked loop (DLL) circuit and a method for generating transmission core clock signals are provided, where the DLL circuit receives an applied external clock signal and generates a transmission core clock signal, the DLL circuit includes a delay circuit unit and a transmission core clock signal generating unit, the delay circuit unit delays the external clock signal through a plurality of delay units configured in a chain type and outputs a plurality of reference clock signals having different phases, the transmission core clock signal generating unit independently selects and controls two reference signals from the plurality of reference clock signals and thus independently generates transmission core clock signals by the number corresponding to ½ times the number of reference clock signals, and the transmission core clock signals have different phases and a period equal to a period of the external clock signal, wherein transmission core clock signals having a precise phase difference are generated individually and independently.
Owner:SAMSUNG ELECTRONICS CO LTD

Quadrature frequency doubler with adjustable phase offset

The present invention provides an improved frequency doubling circuit, with adjustable phase offset. Briefly, rather than using the traditional equations cos (2ωt)=cos 2(ωt)−sin 2(ωt) and sin(2ωt)=2 sin(ωt)cos(ωt), the quadrature output signals are generated utilizing mixers, each having two input signals, separated in phase by the same offset. This minimizes the effects of the non-linearities introduced by the mixer, which therefore reduces amplitude mismatch between the quadrature signals. Also, the phase offset of the quadrature output signals can be tuned and calibrated using a phase shifting circuit. This phase shifting circuit realizes a tuning range of approximately 5° in programmable steps. This combination of circuits can be used to minimize the amplitude mismatch and phase errors, thereby reducing the amplitude of and interference caused by transmission of the image frequency to the receivers input.
Owner:EDGEWATER WIRELESS SYST

7-mode gain and output power controllable K-band power amplifier

The invention relates to a technology of millimeter wave wireless communication and specifically relates to a 7-mode gain and output power controllable K-band power amplifier. The K-band power amplifier comprises a power supply, a control power supply, a Vdd end, a Vb end, control ends Vc1, Vc2 and Vc3, an input end, an output end and an earth wire. The Vdd end and the earth wire are in bridge joint with a positive end and a negative end of the power supply. The Vb end is connected with a bias voltage. The control ends Vc1, Vc2 and Vc3 are connected with the positive end of the control power supply. The K-band power amplifier also comprises a first Balun, a first input matching circuit, a second input matching circuit, a first drive circuit, a second drive circuit, an interstage matching circuit, a gain control stage, an interstage transformer transformer, a power-stage circuit, a first output matching circuit, a second output matching circuit and a second Balun which are connected in sequence. The amplifier is characterized by controllable 7-mode power and gain pseudo number, high power gain and high output power. The amplifier is low in transmission loss, low in phase error, low in return loss and high in port isolation degree.
Owner:WUHAN UNIV

Method and system for calibrating interference of space-based interferometric imaging radar altimeter

The invention relates to a method and system for calibrating interference of a space-based interferometric imaging radar altimeter. The method comprises the following steps: determining the radar viewing angle of each pixel point of a reference target according to the altitude information of the reference target as well as rail and slant distance parameters acquired by the space-based interferometric imaging radar altimeter; performing polynomial fitting on the spatial variation relation between the unrapping phase and the radar viewing angle; determining the sensitivity of the unwrapping phase and the slant distance on the radar viewing angle separately; determining the length and the inclination angle of a base line; and determining interferometric phase offset. The system comprises a radar viewing angle calculation module, a fitting coefficient calculation module, a sensitivity calculation module, an interferometric base line determining module and an interferometric phase offset determining module. Estimation of the interferometric base line and the interferometric phase offset can be separated by fitting and estimating the sensitivity of the unwrapping phase on the radar viewing angle, so that the three parameters such as the length of the base line, the inclination angle of the base line and the interferometric phase offset, can be completely estimated.
Owner:TECH & ENG CENT FOR SPACE UTILIZATION CHINESE ACAD OF SCI

Phase interpolator

A phase interpolator includes a first to a fourth differential pair. Each of the differential pairs includes a first and a second transistor and a stabilizing capacitor connected between a source coupled node and a reference voltage. The phase interpolator also includes a plurality of current sources and a group of switches to switch connections between the source coupled nodes of the differential pairs and the current sources so that (i) a first operating current is supplied to a first selected one of the first and second differential pairs and (ii) a second operating current is supplied to a second selected one of the third and fourth differential pairs. Drains of the first transistors in the differential pairs are commonly connected and drains of the second transistors in the differential pairs are commonly connected to form a first and a second output node so that a differential output signal is output.
Owner:MEGACHIPS

Legendre-orthogonal-decomposition-baesd curve motion trajectory SAR wave-number domain imaging method

ActiveCN110208799AExact slope distance history expressionReduce phase errorRadio wave reradiation/reflectionAzimuth compressionTime domain
The invention relates to a Legendre-orthogonal-decomposition-baesd curve motion trajectory SAR wave-number domain imaging method. The method comprises: constructing a slant range history expression ina curved motion trajectory mode by using a three-dimensional speed and a three-dimensional acceleration; carrying out polynomial expansion on the constructed slant range history expression and carrying out keeping to the fourth order; transforming an SAR echo signal corresponding to the slant range into a two-dimensional frequency domain to obtain a two-dimensional frequency spectrum; with a Legendre orthogonal polynomial, spreading the two-dimensional frequency spectrum for a distance range frequency and carrying out keeping to a third order; carrying out phase compensation based on a two-dimensional frequency spectrum developed based on Legendre and completing distance migration correction and distance range focusing; and carrying out azimuth compression in a distance-Doppler domain andcarrying out transformation in a two-dimensional time domain to obtain a focusing image. Therefore, a target imaging blurring problem at the scene edge is solved.
Owner:HUAQIAO UNIVERSITY

Combined X-band five-bit phase shifter based on active and inactive structures

The invention discloses a combined X-band five-bit phase shifter based on active and inactive structures, and mainly solves the problems of large gain error and low phase shift precision in the priorart. The phase shifter comprises filters (1), an active balun (3) and switches (4); multiple filters and switches are respectively provided and are alternately connected; the last switch is connectedwith an input end of the active balun; an output end of the active balun is connected with an orthogonal signal generator (2) and is used for generating positive and negative in-phase signals and positive and negative orthogonal signals; and an output end of the orthogonal signal generator is connected with a one-in-four circuit (5), and is used for selecting one path of signals from four paths ofsignals, namely the positive and negative in-phase signals and the positive and negative orthogonal signals to output, thereby implementing transformation of the signals among four quadrants. The phase shifter has the advantages of small gain error and high phase shift precision, and can be used in a radio-frequency integrated circuit in which a high-precision phase shifter is needed by a radio-frequency microwave phased array receiver.
Owner:XIDIAN UNIV

Multimode multi-frequency combined antenna and GNSS receiver

The present invention relates to a multimode multi-frequency combined antenna and a GNSS receiver. The multimode multi-frequency combined antenna includes a first shielding cover, a GNSS radio frequency board, a GNSS antenna, a bracket, a network main antenna, a network diversity antenna, and two WIFI Bluetooth antennas. For the multimode multi-frequency combined antenna described above, an integrated design idea is used, an optimized design layout is reasonable, clearing of an antenna area is reasonable, network main antenna and diversity antenna are separated from each other, WIFI Bluetoothantennas are separated from each other and are diagonally placed, and a physical distance is increased. In this way, not only isolation is improved, but also phase center stability of the GNSS antennacan be ensured, and a phase error caused by geometric asymmetry of the GNSS antenna is reduced. In addition, a reasonable structural design can ensure effective reception and transmitting of satellite signals, network signals, and WIFI Bluetooth signals with high-precision. In addition, the network antenna is compatible with the main diversity antenna, and a signal received by the antenna in a position in which the spatial signal is stronger is fully utilized, a signal to noise ratio is higher, and signal transmission quality is better.
Owner:GUANGZHOU HI TARGET SURVEYING INSTRUMENT CO LTD

Polarization self-matching type wave beam reversing method

ActiveCN103794881ALower the local oscillator frequencyReduce phase errorAntennasAntenna polarizationCommunications system
The invention discloses a polarization self-matching type wave beam reversing method. The polarization self-matching type wave beam reversing method aims to solve the problem that in systems such as microwave energy transmission systems and energy-carrying communication systems, when the antenna polarization mode of a receiving end is unknown to a sending end or the polarization direction is changed due to movement or rotation of the receiving end, the antenna polarization mode of the receiving end and the antenna polarization mode of the sending end are not matched, link loss is increased, and energy or information transmission efficiency is affected. The polarization self-matching type wave beam reversing method comprises the steps that guide signals are received through a square double-fed SMD dual polarized antenna unit of an antenna array of the sending end, one receiving branch of two receiving branches passes through a 180-degree delay line to enable the phase differences of the two branches of signals to be reversed, polarization rotation is completed, and dual polarized antennae are fed in for transmission, the guide signals are received in a frequency-mixing mode by several times to enable phase distribution of conjugation to be obtained, and transmitted wave beams are made to aim at the receiving end in a self-adaptive mode. The polarization self-matching type wave beam reversing method has the advantages that priori knowledge such as the positional information of the receiving end and the polarization mode of a receiving antenna is not needed, a reversing array can generate transmitting wave beams in the direction identical to the direction of the guide signals and with orthorhombic polarization modes, and duplexing work is achieved.
Owner:XIAN INSTITUE OF SPACE RADIO TECH

Determination method of antenna array phase response parameter with unknown signal direction

The invention belongs to the technical field of electronic information and discloses a determination method of an antenna array phase response parameter. The determination method comprises initialization processing. A sample autocorrelation matrix of an antenna array receiving signal vector is determined. A signal subspace matrix and a noise subspace matrix of the sample autocorrelation matrix are determined. A direction matrix is determined. A signal guiding vector is determined. Finally, an antenna array phase response parameter is determined. According to the method, the signal subspace matrix of the antenna array receiving signal vector is used for establishing a non-phase vector and the direction matrix, and by determining signal direction, the signal guiding vector and the like, the antenna array phase response parameter is determined. The method is used for determination, and the correlation coefficient of the result and a practical phase response parameter vector is larger than 0.99. Accordingly, under the situation that signal direction is unknown, the antenna array phase response parameter can be determined effectively, the method has the advantages that errors between the determined phase response parameter and the practical phase response parameter are small, and similarity is high.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA +1

Nonlinear phase error correcting method based on digital projection three-dimensional measuring system

The invention discloses a nonlinear phase error correcting method based on a digital projection three-dimensional measuring system. The system comprises the steps of setting a stripe space period as M, setting an actual stripe phase shifting step number as N, setting a phase shifting step number of a phase error stripe pattern as N', setting t as a coefficient, generating an NXN' step phase shifting stripe pattern by a computer according to the stripe pixel period M= tXNXN', projecting the stripe pattern onto a white board by the three-dimensional measuring system, and collecting an actual phase shifting stripe pattern; extracting the collected phase shifting stripe pattern, obtaining N' groups of N step phase shifting stripe patterns, calculating actual phases and corresponding NXN' stepideal phases, obtaining phase errors, and obtaining N' phase error patterns; and calculating the amplitude of the phase shifting stripe pattern by a least square algorithm, calculating a numerical value of a gamma correction factor of each pixel according to a relation between the amplitude and the gamma correction factor, correcting the original stripe pattern generated by the computer accordingto the gamma correction factor, and projecting the corrected phase shifting stripe pattern by adopting the three-dimensional measuring system to perform three-dimensional reconstruction.
Owner:SHENZHEN ESUN DISPLAY

Balanced hybrid coupler network

An electrical processing network including a first set of ports and a second set of ports electrically coupled to the first set of ports. The first set of ports are for a first set of signals with approximately 0° and 180° relative phase. The second set of ports are for a second set of signals with approximately 0°, 90°, 180° and 270° relative phase.
Owner:HOOVER LOWELL R

Permanent magnet linear motor control method

The invention discloses a permanent magnet linear motor controller which controls a motor by means of a combination of an H-infinity robust controller, a ZPETC (zero phase error tracking controller) and an interference observer. The ZPETC is used as a feed-forward controller of a system and reduces phase errors by means of zero point elimination. The interference observer eliminates high-frequency interference signals by being provided with a low-pass filter. The H[sigma] robust controller utilizes a mixed-sensitivity design method, comprehensively considers balance between sensitivity and robustness, and sets the optimization of the parameters of the H-infinity robust controller by performing fuzzy judgment on the results of the ZPETC and the interference observer. The controller combining the above three methods optimizes the dynamic performance and the stable performance of a permanent magnet linear motor, and may effectively improve positioning precision, a response characteristic, and an anti-interference capability.
Owner:SOUTHEAST UNIV
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