80results about How to "Reduce mutual coupling effects" patented technology

The present invention discloses a mutual coupling condition-oriented bistatic MIMO (multiple-input multiple-output) radar angle estimation method. According to the method, radar data which have been subjected to matched filtering are expressed as a third-order tensor model by means of the multi-dimensional structure of array signals; since a uniform linear array mutual coupling matrix has a strip-shaped Toeplitz feature, the common scale conversion feature of a part of an array element directional matrix is utilized to eliminate the influence of mutual coupling; on the basis of a forward-backward smoothing technique and a unitary transformation technique, the augmented output trilinear model of decoupling-post data is constructed; and joint DOD (direction-of-departure) and DOA (direction-of-arrival) estimation is related with the trilinear model; and a target DOD and DOA are estimated through the least squares method. Compared with a traditional algorithm, the bistatic MIMO (multiple-input multiple-output) radar angle estimation method under the mutual coupling condition can effectively deal with situations where mutual coupling exists between a transmitting array and a receiving array, can automatically match the estimated DOD and DOA, and can reduce computational complexity by using a feature that trilinear decomposition only involves real number operation.

The invention provides a joint parameter estimation method based on a distributed polarization sensitive array. The joint parameter estimation method includes dispersedly setting array element components of a polarization sensitive array consisting of electric dipole pairs in the space so as to form the distributed polarization sensitive array, dividing the distributed polarization sensitive array into a first sub array and a second sub array according to sequence of array elements, acquiring a covariance matrix of incident signals after the distributed polarization sensitive array receives the incident signals, establishing a signal sub space according to the covariance matrix, dividing the signal sub space consisting of the covariance matrix into a first sub matrix and a second sub matrix according to sequence of line numbers of the matrix, and acquiring estimation to angle of arrival and polarization parameter of the incident signals according to rotational invariance of the first sub matrix and the second sub matrix.

The invention provides a simple and practical indoor polarization scattering measurement system, which is used for obtaining high-polarization-purity scattering data based on a vector network analyzer. The indoor polarization scattering measurement system is formed by the vector network analyzer, antennas, a main control computer, a microwave shielding darkroom and a turntable control cabinet. By filling a part of absorbing materials between the antennas, influence of mutual coupling between the antennas is reduced physically;and after converting broadband step frequency domain data to a time domain, near-end antenna mutual coupling signals are removed by utilizing selectivity of a time domain wave door. High-purity target polarization scattering characteristic data is obtained through a method of setting appropriate parameters and the like for the step frequency signals, and polarization data purity is higher than 45 dB; and the polarization scattering measurement system is simplified, and a lot of production cost is reduced.

The invention discloses an arrival direction estimation method based on conjugation expansion. The method comprises the following steps of: firstly calculating and receiving a second order statistic between signals, obtaining a conjugation matrix of an oriented matrix by utilizing the property of a delay self-correlation function, then constructing a new pseudo snapshot matrix by utilizing delay sampling of an extensible vector, and finally estimating an arrival direction of a signal on the matrix by adopting a fourth-order cumulant method. By virtue of a signal arrival direction estimation method based on array extension, the number of estimated signal arrival directions is greatly increased and signal arrival direction estimation accuracy can be improved.

The invention discloses a multiple-input multiple-output imaging antenna layout method of a close-distance planar array. The method comprises the steps that firstly, the size of a shortest effective composite array of an imaging system and the size of a planar array element antenna are determined; secondly, the minimum distance between similar receiving and transmitting antenna centers is determined; thirdly, the total number of receiving and transmitting antenna elements of a minimum composite array of the imaging system and the size of the minimum composite array are determined; fourthly, the number of total receiving and transmitting array elements of the imaging system, the number of antenna equivalent phase centers of the imaging system and the size of the planar array of the imaging system are calculated; fifthly, the distribution of the geometrical center positions of the transmitting and receiving array element antennas of the imaging system is calculated; sixthly, the layout is carried out according to the distribution of the geometrical center positions of the transmitting and receiving array element antennas of the imaging system. According to the layout method, the problem that in the planar array MIMO imaging, the length of the effective composite array is affected by the observation distance is solved, and on the premise of guaranteeing the quality of close-distance microwave images, the data acquiring efficiency is further improved.

The invention belongs to the technical field of radar electronics, in particular relates to a large-array surface phased array radar antenna. The large-array surface phased array radar antenna comprises an array surface antenna and a support rack, wherein the array surface antenna comprises antenna line oscillators and antenna row oscillators, the number of the antenna row oscillators is equal to the number of the antenna line oscillators, the distance between two adjacent groups of antenna line oscillators is equal to the distance between two adjacent groups of antenna row oscillators, each antenna line oscillator and each antenna row oscillator cross to form a cross meshed structure of the array surface antenna, top end surfaces of dipoles after each antenna line oscillator and each antenna row oscillator cross are arranged on the same plane, symmetric surfaces of two adjacent dipoles on each group of antenna line oscillator are arranged on a plane where the group of antenna line oscillators are located, and the symmetric surface of each dipole on each group of line oscillators is arranged on a plane where the group of antenna row oscillators are located. By the large-array surface phased array radar antenna, the usage quantity of T/R modules can be effectively reduced on the premise that the working accuracy of the radar antenna can be ensured, and the purpose of effectively controlling cost is further achieved.

The invention belongs to the technical field of a helicopter structure test and relates to a strain gauge arranging and decoupling method for asymmetrical structures of a helicopter rotor paddle (including a tail paddle) and the like, which is widely suitable for load test work for asymmetrical structures (for example an air blower blade, a turbine blade and the like) of other industries. The gauge arranging technology and the physical decoupling method disclosed by the invention overcome the defect that a common analyzing and decoupling method is insufficient in timeliness, can timely and accurately obtain swing and shimmy strains, the measured value is the true swing strain (or shimmy strain), so that great convenience is brought to a test flight or a measuring site as well as timely judgment. Moreover, in practical load measuring, compared with the technology in the invention and a conventional strain gauge arranging technology and analyzing and decoupling method, the processing workload for the test data is relatively less, namely the data processing workload can be saved through the gauge arranging technology and the physical decoupling method, and the working efficiency is improved.

The invention discloses a less-rare-earth multi-excitation-source double-stator flux-switching memory motor, which belongs to the technical field of motor body design and operating principles. Coaxial outer stators, rotors and inner stators are sleeved together in turns from outside to inside to compose the memory motor, wherein a radial air gap exists between the outer stators and the rotors, the rotors and the inner stators, the outer stators are composed of armature core teeth, fault-tolerant teeth and stator yokes, and the rotors are composed of a rotor support, a magnetic silicon steel block and a magnetic insulation block, and meanwhile, the inner stators are composed of the inner stator core and a combined permanent-magnet cell block. The double-stator structure of the motor realizes the separation of armature winding and permanent magnet and solves the problem that multiple excitation sources inside the traditional flux-switching permanent magnet motors restrain each other, thereby easily increasing motor power density and torque density. The memory motor maintains high air-gap flux density and ensures of the motor power density and the torque density, meanwhile, the consumption of rare-earth permanent-magnetic materials is effectively lowered. On the other side, the memory motor can realize flexible adjustment of a motor air-gap field and expand the range of speed operation.

The invention provides a dual polarized antenna array and a dual polarized phased-array antenna. The dual polarized antenna array comprises a polarized feeder component, a coupling slot component, a plurality of radiation patches and a metallized via hole component, wherein the polarized feeder component comprises a first polarized feeder and a second polarized feeder, the coupling slot componentcomprises a plurality of first coupling slots and a plurality of second coupling slots perpendicular to each other, the radiation patches are positioned at the upper layer of the coupling slot component, and a plurality of metallized via holes arranged side by side are positioned between the first coupling slots and the second coupling slots. Through introducing the metallized via hole, each polarized feed network is isolated, so that the cross polarization component caused by cross coupling between the feeders can be effectively inhibited, and the cross polarization isolation of the dual polarized phased-array antenna provided by the scheme is more than 35dB.

The invention provides a log periodic feed source array based on spaceborne multi-beam antenna space three-dimensional structure layout. The log periodic feed source array is composed of five groups of high-frequency feed units, four groups of low-frequency feed units and a composite material supporting component. The mutual coupling influence on electrical performance of the feed source array between antennas can be reduced to the largest extent through three-dimensional structure layout and unit array distribution optimization under the requirement of spaceborne limited space layout so that the multi-beam coverage requirement of broadband and high gain of the antennas can be realized; the units and the supporting component are simple in structural form and high in reliability so that great rigidity-to-gravity requirement of the feed source array can be realized; and the special composite material and ingenious structural design are adopted, shielding influence of the supporting component on the electrical performance of the formed high-frequency and low-frequency feed units is enabled to be minimized under the condition of meeting the main structural strength of the feed source array, and the space environmental requirements can also be met.

The invention provides a satellite navigation receiver anti-interference method and system based on a switched antenna array. The method specifically includes the following steps that S1, the switchedantenna array receives GNSS and interferential complex baseband signals; S2, switching operation is carried out on the switched antenna array, and the GNSS and interferential complex baseband signalsare transformed into a baseband signal after switching; S3, the switched baseband signal is sampled and transformed into a digital signal; S4, the digital signal is multiplied by a modulated local carrier signal after weight modulation and relevance addition is carried out, the time of relevance addition is synchronized with that of switching operation in the step S2, and an output array after relevance addition is obtained; and S5, synthetic beam forming is achieved. According to the satellite navigation receiver anti-interference method and system based on the switched antenna array, influence of channel deviation and mutual coupling on the switched antenna array is reduced, compared with conventional antenna arrays, better interference suppression performance and lower hardware cost are achieved. The invention is applied to the field of navigation receiver development.

A radio frequency transmitter includes: power amplifier stages having paired output terminals, where a pair of output terminals is coupled to a respective amplifier stage. A power combining arrangement includes: first paired input terminals, second input terminals, such that each input of the first paired input terminals is coupled to the same second input terminal; and a power transfer circuit coupling the second input terminals. A first pair of cross coupled bond wires couples a pair of amplifier stage output terminals with a different second input terminal via terminals of different pairs of the first paired input terminals; and a second pair of cross coupled bond wires overlays the first pair of cross coupled bond wires and couples a further pair of amplifier stage output terminals with a different second input terminal via terminals of different pairs of the first paired input terminals.

The invention discloses a broadband radio frequency identification reader-writer antenna with a wide circularly polarized beam. The antenna comprises triangular defect radiation patches, a circular coupling patch, a grounding probe, a feed probe, a feed network, a dielectric plate, a metal floor, a coaxial connector and a short-circuit pin. According to the structure, the cross-shaped gap betweenthe triangular defect radiation patches is used for radiation to broaden the circularly polarized beam width of the antenna; the grounding probe effectively reduces the sizes of the triangular defectradiation patches; the impedance matching performance of the antenna is improved by the gap capacitance between the triangular defect radiation patches and the circular coupling patch; the introduction of the air layer improves the bandwidth of the antenna; the feed network based on the hybrid ring and the TRD coupler eliminates the mutual coupling influence between the triangular defect radiationpatches, and achieves good circular polarization performance.

The invention provides an antenna filtering circuit in an electronic terminal, an antenna filtering method and an electronic terminal. A metal frame of the electronic terminal is divided into at leasttwo parts through at least one slit. Each of the at least two parts is made into an independent antenna, so that at least two antennas are formed. Any one of the at least two antennas is determined as a target antenna. The antenna filtering circuit includes a multi-channel changeover switch and a plurality of filters, wherein a first connection end of the multi-channel changeover switch is connected to a first predetermined position of an antenna adjacent to the target antenna, a second connection end of the multi-channel changeover switch can be connected to first ends of the different filters, and a second end of each filter is grounded. By adopting the antenna filter circuit in an electronic terminal, the antenna filtering method and the electronic terminal in the exemplary embodimentof the invention, the isolation degree between adjacent antennas can be increased, the mutual coupling effect between adjacent antennas can be reduced, and the overall radiation performance of antennas can be improved.

The invention provides a base station antenna with a same-frequency mutual coupling effect reducing device, which comprises a metal base, an outer cover, a plurality of columns of antenna units and decoupling devices, and is characterized in that the decoupling devices are arranged between two adjacent columns of antenna units; the frequencies of the multiple columns of antenna units are the same, and the distance S between every two adjacent columns of antenna units is smaller than 1/4 of the center frequency wavelength of the antenna units and larger than 1/10 of the center frequency wavelength of the antenna units; the length L of the decoupling device is greater than the length of the antenna unit, the height H is equal to the height of the antenna unit, and the width D is greater than 1/16 of the central frequency wavelength of the antenna unit. The base station can be provided with more antennas by reducing the distance between the multiple columns of antenna units so as to enlarge the communication capacity of the base station, and the decoupling device is arranged between the two adjacent columns of antenna units so as to reduce the mutual coupling effect between the adjacent antenna units, so that the mutual coupling effect between the antenna units is effectively reduced under the condition that the design size of the base station antenna is met.

The invention discloses a wideband and wide-angle circularly polarized phased array unit. The wideband and wide-angle circularly polarized phased array unit comprises a back cavity structure, an upper-layer dielectric substrate, a lower-layer dielectric substrate and a feeding dielectric substrate, wherein a cross microstrip patch is printed on the upper-layer substrate, two feeding points are arranged on two cross arms of the cross microstrip patch, each feeding point is provided with a capacitor feeding probe, no copper is coated on dual surfaces of the lower-layer substrate, and a Wilkinson power divider and a 90-degree phase shift microstrip line are printed on the feeding dielectric substrate. The two feeding points are respectively arranged on the two cross arms, and feeding is achieved by the Wilkinson power divider and the 90-degree phase shift microstrip line; by introducing an annular gap, a capacitance component is generated to offset an inductance component brought by the feeding of a long probe and achieve wideband matching; and by the wideband and wide-angle circularly polarized phased array unit, the beam width and the working bandwidth of an antenna can be effectively expanded, meanwhile, the mutual coupling effect during antenna array forming is reduced, so that the antenna becomes a relatively ideal circularly polarized phased array unit.

The invention provides a dual-polarized antenna array and a dual-polarized phased-array antenna. The dual-polarized antenna array includes two antenna modules arranged in a 180-degree rotationally symmetric manner. Each antenna module includes a polarization feeder line component, a coupling slit component, and a plurality of a radiation patches. The polarization feeder line component includes a first polarization feed line and a second polarization feed line. The first polarization feed line and the second polarization feed line are both disposed on the same side of a rotation center in the arrangement direction. The coupling slit component includes a plurality of mutually perpendicular first coupling slits and a plurality of second coupling slits. Each radiation patch covers a first coupling slit and a second coupling slit. In the dual-polarized antenna array, the rotationally symmetric arrangement pattern make adjacent line arrays generate inverted influences, so that the cross-polarization components generated by nonideal factors cancel each other out, the mutual coupling effect between different polarization feed networks is reduced to some extent, and finally the polarizationisolation of the obtained array antenna may be as high as over 30dB.

A horizontally polarized small UHF slot antenna for radio communication uses the end feeding by 1/4 wavelength, and features that two reverse L-shaped slots with open lower end are symmetrically made on metallic tube, and connected by 1/2-wavelength transmission line. Its advantages are high gain, horizontal polarization receiving, low sensitivity to frequency, and stable direction diagram.

The invention discloses a three-dimensional non-orthogonal tracking and scanning test head calibrating method, and belongs to the field of precise instrument measurement. The three-dimensional non-orthogonal tracking and scanning test head calibrating method is designed for a coordinate measuring machine, a precise numerical control machine tool and other precise measuring instrument on the basisof a three-dimensional coordinate measuring system. By means of the method, through the coupling effect of a cubic-term fitting decoupling sensor, in cooperation with a corresponding data collecting method, by introducing a self-adaptive genetic algorithm for solution, the calibrating precision is greatly improved, and meanwhile external parameters and internal parameters of a test head are calibrated and the calibrating operation process is simplified. The method is suitable for the three-dimensional non-orthogonal tracking and scanning test head.

The invention belongs to the technical field of antenna feed, and particularly relates to a compact type microstrip line power distribution network. The network comprises a first power distribution subnetwork and a second power distribution subnetwork, wherein each of the first power distribution subnetwork and the second power distribution subnetwork is divided into six paths. The first power distribution subnetwork is connected with the second power distribution subnetwork through Wilkinson power dividers with phase shifters. Other branch ports of the first power distribution subnetwork and other branch ports of the second power distribution subnetwork are connected with phase shift microstrip line segments. Eight coaxial feed probes are correspondingly arranged on ends of four phase shift microstrip line segments and on the total ports of the four groups of the Wilkinson power dividers, vertically penetrate through a medium plate and then are connected to a metal group place. The network is advantaged by compact size, small amplitude of each port and small phase position error, and an antenna applying the power distribution network can be allowed to have good performance of high pointing accuracy and low minor lobe.

The invention discloses an array method and an array system of a satellite communication-in-motion antenna array. The invention determines the dimension of the array element position matrix accordingto the size of the antenna array and the number of array elements, can simultaneously consider the distributable space of the array elements and the number of the array elements, and maximizes the degree of freedom of the array element distribution. The optimal abscissa random variable matrix, the optimal ordinate random variable matrix and the optimal weight matrix are obtained by solving the optimization function to minimize the maximum sidelobe level. As can be seen, the present invention provides a method for reducing the number of pixels with a minimum array element interval constraint, element total constraint, the problem of antenna size constraints is transformed into a stochastic optimization problem with only upper and lower bounds, Successfully converting the multi-constrained strip optimization problem into an unconstrained optimization problem can effectively improve the search efficiency of the antenna array, avoid the infeasible solution, thus effectively reduce the mutual coupling effect between the array elements, and reduce the cost, weight and power consumption of the antenna on the premise of ensuring the antenna performance.

The invention discloses a millimeter wave radar antenna. The millimeter wave radar antenna is of a cover type structure and consists of an antenna layer and an antenna cover type structural member; the antenna layer is arranged on the antenna cover type structural member, and is fixedly connected with a printed circuit board through the antenna cover type structural member; and an array antenna isprinted on the antenna layer. According to the array antenna, the occupied area of a chip is utilized, so that a larger design space is obtained; the implementation of different millimeter wave arrayantenna pattern forms is facilitated; the isolation degree between array antennas can be improved; and the mutual coupling effect between the array antennas can be reduced.