119 results about "Directivity diagram" patented technology

The invention discloses an S-PIN-diode-based directional diagram reconfigurable disk microstrip antenna, which comprises a circular patch for generating primary radiation and six fan-shaped parasitic patches with special U-shaped slots. An S-PIN diode is arranged between the circular patch and each parasitic patch, and the turning-on and turning-off states of each S-PIN diode are controlled by controlling the bias voltage of the S-PIN diode. When the antenna works, a probe is connected with the circular patch for direct feed, and is connected with one parasitic patch through the corresponding S-PIN diode, so that surface current flows towards the patch, and a directional diagram can be deflected towards the direction. The directional diagram can be scanned in all directions by sequentially conducting adjacent S-PIN diodes. The antenna is small in size, easy to integrate and wide in application range, works within the frequency bands of 802.11g and 802.11p, and has broad application prospect, and the directional diagram can be scanned in all directions.

The invention provides a system for testing the aerial performance of a wireless USB modem and comprises a darkroom, a rotating floor that is arranged in the darkroom, a testing antenna and a computer, wherein, the wireless USB modem is connected with the started computer through a USB wire, and the computer is fixed in the top end of a rotating shaft that is vertical to a plane of the rotating floor; the USB modem is arranged in a proper position of the darkroom for implementing the great circle test of the USB modem. The invention further provides a method for testing the aerial performance of the wireless USB modem. Therefore, the invention can better utilize an OTA testing darkroom of existing cellphones, the hardware system of the rotating floor and the software system, and a three-dimensional directivity diagram and TRP and TIS data which are acquired from the testing can reflect the radiation and receiving characteristics of the antenna.

The invention relates to a reconfigurable antenna based on a conformal active frequency selection surface. Bias voltage generated by control circuits (5) on the upper surface and the lower surface of a cylinder is added to two ends of each line of crosses, so as to control the on / off states of diodes (3). When the diodes are in switch-on and switch-off states, the frequency response characteristics of the frequency selection surface are respectively high reflection and high transmission. The conformal active frequency selection surface utilizes the frequency response characteristics to convert an omnidirectional diagram of a dipole antenna into a directed-radiation directional diagram, and can achieve the purpose that the directed-radiation directional diagram can scan at 360 degrees in an X-O-Y plane. The invention is suitable for the dipole antenna with the operating frequency below 2.5GHz; and when the omnidirectional diagram of the dipole antenna is converted into the directed-radiation directional diagram, the gain can be improved by about 8dB, and the final gain can reach about 11dB, thereby realizing the high-gain reconfigurable antenna. The reconfigurable antenna provided by the invention has the advantages that the structure is simple, and the on / off states of the diodes are easy to control.

The method relates to a method for designing an antenna by improving the side lobe characteristics of an array wave beam directivity diagram, belonging to the technical field of array antennae. The method comprises the following steps of: setting an expected response directivity diagram A; under the unrestraint condition, determining a array wave directivity diagram B according to a minimum mean square error criterion; selecting a side lobe S to be optimized to determine an interval Omega; under the condition of taking a principle that the directivity diagram amplitude at a k equal division point is zero in the Omega as a constrict condition, calculating an optimal weighting vector Wopt(k) of an array, approaching to the directivity diagram A, according to the minimum mean square error criterion under the corresponding constraint condition to obtain a directivity diagram Ck, and searching the peak value p1(k) and a peak value p2(k) of side lobes at the left side and the right side of the k equal division point in the Ck; and marking Mr (k)=max{pr2(k), pr1 (k)}, searching a maximum value Mr (krm) in all Mr(k), determining the corresponding Wopt (krm) and a wave beam directivity diagram D, and carrying out array antenna design according to the Wopt (krm) and D. The method disclosed by the invention is used for designing the array antenna by improving the characteristics of the side lobes at the single side or both sides without carrying out hardware improvement on the original array and has the advantages of good flexibility, low cost and good effect.

The invention discloses a preprocessing method for deformation data of a panel of a reflector antenna. The method takes deformation data of the reflector antenna as a processing object, and selects different data preprocessing methods according to different data types in engineering of a sector panel sampling point three dimensional coordinate, a triangular unit nodal coordinate and a quadrilateral unit nodal coordinate; an area coordinate and a polar coordinate are introduced to simplify an integral domain of any unit; the efficiency of the numerical integration is improved by using the Gauss integral formula; the number of lobes of a directional diagram are evaluated by referring to the half power lobe width; the number of discrete points of each lobe are picked up to determine the discrete precision of the directional diagram; according to the discrete precision of the directional diagram, the numerical integration calculation is repeated, and a complete far field directional diagram of a deformed reflector antenna is drawn in the end. A simulation result shows that the invention can not only effectively reduce the data processing time, but also improve the calculating precision of the antenna directional diagram; thereby the preprocessing method can be applied to the preprocessing of the deformation data of the reflector antenna under a plurality of engineering situations.

The invention provides a system for testing the aerial performance of a wireless USB modem and comprises a darkroom, a test board that is arranged in the darkroom, a testing antenna and a computer, wherein, the wireless USB modem is connected with the started computer through a USB wire, and the computer is fixed on a plane of the testing test board; the USB modem is arranged in a proper position of the darkroom for implementing the cone cut test of the USB modem. The invention further provides a method for testing the aerial performance of the wireless USB modem. Therefore, the invention can better utilize an OTA testing darkroom of existing cellphones, the hardware system of a rotating floor and a software system, and a three-dimensional directivity diagram and TRP and TIS data which are acquired from the testing can reflect the radiation and receiving characteristics of the antenna.

The invention discloses a three-dimensional hair reconstruction method based on a single picture. The method comprises the steps of 1) strip mesh hair model generation, 2) strip mesh hair model database construction, 3) picture-based hair style retrieval (hair style retrieval); and 4) strip mesh hair and head fusion (hair fusion). The main process comprises the steps that a hair model is transformed into a strip mesh model; a strip mesh hair model database is constructed; an input image is given, and a hair shape retrieval map is extracted from the hair region thereof; a hair shape feature vector and a hair directivity diagram are used as retrieval information; a hair model most similar to the retrieval information is retrieved from the strip mesh hair model database; and finally the hairmodel is attached to a human head model. The method provided by the invention realizes three-dimensional hair reconstruction for a single picture, and can be applied to hair reconstruction and hair animation.

The invention relates to a millimeter wave multi-feed-source compact range testing system which comprises nine millimeter wave feed sources (1, 2, 3, 4, 5, 6, 7, 8 and 9) at different positions, a reflecting surface (10), a turntable system (11), a direct leakage baffle (14), an antenna to be tested (15) and a reference antenna (16). The phase center of the central feed source is located at the focus of the reflecting surface, the other eight feed sources are located near the focus, and the relative position of each feed source and the central feed source is determined according to the position of a dead zone, the deflection angle of the dead zone and the geometric dimension of the reflecting surface. When millimeter-wave antenna measurement is carried out, directional diagram testing canbe carried out on an antenna at multiple angles at the same time by rapidly switching the working states and polarization modes of different feed sources, and the testing efficiency of the millimeter-wave antenna is greatly improved.

The invention discloses a differential dual polarization patch antenna based on a split-ring resonator. The antenna comprises a bottom layer antenna reflection plate, wherein two split-ring resonatorsare arranged on the antenna reflection plate; the centers of the two split-ring resonators are connected and the two split-ring resonators are crossed; inner cores of four coaxial cables are respectively welded to the two ends of the two split-ring resonators; the four welding points are in a center symmetrical distribution state; a microband patch is formed on the top of the split-ring resonators. The differential dual polarization patch antenna based on the split-ring resonator disclosed by the invention has the advantages that the whole antenna is of a center symmetrical structure; the differential feed symmetrical resonance ring stimulation patch is used; the advantages of small dimension, compact structure, wide frequency band, high port isolation degree, high directivity diagram polarization isolation degree and the like are realized; the differential dual polarization patch antenna can be widely applied to the wireless communication fields of radar and base station communication, satellite communication, wireless local area networks and the like; the upper layer microband patch is a square patch, so that the mutual orthogonal intersection radiation mode is stimulated.

The invention relates to a broadband ridge sheet outward-extending four-ridge circular horn feed source antenna, wherein horn walls and ridges both adopt specific curves and are matched with each other, and the broadband ridge sheet outward-extending four-ridge circular horn feed source antenna can effectively expand the working bandwidth, reduce the voltage standing-wave ratio and remarkably reduce the change of the beam width along with the frequency. The feed probes adopt the semi-rigid coaxial cables connected by two SMA connectors, the two feed probes are vertically installed and are respectively polarized to correspond to two mutually vertical directions of a feed source, and the size of the extending part of each feed probe is processed due to the fact that the distance between ridges is smaller. Meanwhile, the terminal of a ridge curve extends outwards by a specific length and is higher than the terminal of a horn wall curve, so that the effects of broadening the low-frequencybandwidth and controlling a directional diagram are further realized, and meanwhile the phase center position is controlled to be close to the aperture position as much as possible.

The invention discloses an interference suppression method based on a low-correlation space-time two-dimensional random directional diagram. A space-time two-dimensional random directional diagram inmicrowave staring super-resolution imaging is designed, and interference can be more effectively suppressed. The method comprises the steps of generating an orthogonal random phase sequence based on agenetic search algorithm, establishing a phased-array antenna working coordinate system for representing an array element position, calculating a phased-array far-field directional diagram function by utilizing the generated orthogonal random phase sequence, and identifying a target and interference of an array element signal in combination with a sparse reconstruction algorithm. According to theinvention, the random initial phase of the array element signal is generated by using a genetic search algorithm; the designed directional diagram has better orthogonality and performance, the orthogonality of the designed directional diagram is better, target signals and interference signals are separated through matched filtering at the receiving end of the phased array radar, and interferenceof array element signals can be suppressed more effectively. The method is used for anti-interference for radar signals.

The invention discloses a far field distributed parallel sub-array wave beam formation method. The method comprises the following steps: (1), dividing the full array of an energy transducer into a plurality of primary sub arrays, wherein each primary sub array is taken as a basic unit, and all the primary sub arrays form a secondary sub array; (2), performing parallel wave beam formation on all the primary sub arrays; and (3), taking the wave beam formation result of each primary sub array as a basic element of the secondary sub array, and after wave beam extraction, performing secondary sub array wave beam formation. By using the far field distributed parallel sub-array wave beam formation method provided by the invention, a wave beam directional diagram which is close to the main lobe width and the sidelobe peak value of a direct wave beam formation algorithm can be obtained under the condition that a time delay parameter storage space and a calculating load are reduced, the calculating efficiency is greatly improved, and the real-time demand for underwater three-dimensional sonar imaging is satisfied.

The invention relates to a beam forming metasurface structure and method based on amplitude and phase modulation, the beam forming metasurface structure comprises a plurality of metasurface units, and the metasurface units with different structural parameters are uniformly arranged to form the metasurface structure; each metasurface unit comprises three metal layers and two dielectric layers; the first layer, the third layer and the fifth layer are metal layers from top to bottom, and the second layer and the fourth layer are dielectric layers. The metasurface capable of modulating the amplitude and the phase of the electromagnetic wave simultaneously is designed, the structure is simple, the profile is low, and the flexibility of electromagnetic wave regulation and control is improved; the excitation amplitude and phase distribution required by the target directional diagram are calculated based on the Taylor synthesis method and the superposition principle, the method is suitable for synthesis of various far-field directional diagrams, and the calculation method is simple and convenient.

The invention discloses a phase-only multi-beam directional diagram synthesis method based on separation calibration iteration FFT. The method comprises the following steps of generating an initial excitation phase, performing phase-only optimization on initial excitation and selecting an optimal excitation phase. The invention provides an iterative fast Fourier transform (FFT) technology for beam separation calibration, which is inspired by a Schirkunov unit circle, the technology decomposes a multi-beam directional diagram into a plurality of single-beam directional diagrams during each iteration, utilizes forward FFT to solve the excitation of the multiple single-beam directional diagrams, calibrates all the excitation and then adds the excitation, and a calibrated multi-beam directional diagram is obtained through reverse FFT, in addition, an amplitude directional diagram is continuously modified in iteration so as to reduce the side lobe level and lift a main lobe with a low peak value, meanwhile, multiple initial solutions are subjected to multiple times of phase-only optimization so as to achieve the lower side lobe level, and only the excitation phase of an array element is optimized in the method, and the complexity of the feed network can be effectively reduced.

The invention provides an array beam forming method based on a directional diagram reconstruction unit. The method comprises the following steps: 1) an initialization step; and 2) an iteration step: firstly, solving a convex optimization problem by traversing all different directional diagram combination modes, then, taking a directional diagram mode combination with the minimum sidelobe level asan optimal directional diagram mode combination in an iteration process, and outputting the optimal directional diagram mode combination and a corresponding optimal array weight coefficient. Through optimal selection of the array unit directional diagram mode and optimal design of the array weight coefficient, self-adaptive matching of the directional diagram mode and array beam pointing is achieved, the sidelobe level of the array antenna is lowered, and the gain of the array antenna is improved.

The invention discloses a broadband directional diagram reconfigurable antenna based on a PIN diode switch. The antenna comprises a magnetoelectric dipole radiation unit, a dielectric substrate, a reflection floor, an insulation support stud, a metal screw, an inverted L-shaped probe feed structure, a direct current bias circuit, a PIN diode and a multilayer chip ceramic capacitor. A planar electric dipole structure and a direct current bias circuit of the magnetoelectric dipole radiation unit are etched on one side of the dielectric substrate. The planar electric dipole is etched into three sections with different lengths, and the PIN diodes are arranged in gaps of the planar electric dipole. The multilayer chip ceramic capacitor is arranged in the direct current bias circuit to cut off the alternating current. The directional diagram reconfigurable antenna established by the invention has the advantages of simple structure, light weight, wide bandwidth and the like, and the working modes of three different directional diagrams can be realized by controlling the on-off of the four groups of PIN diode switches.

The invention discloses a calibration method of an array antenna. The calibration method comprises the following steps: S1, obtaining an array element directional diagram of the array antenna and theposition of the center of the array element directional diagram; S2, feeding T groups of linearly independent port excitations I1, I2... IT to obtain corresponding T groups of aperture field excitations I'1, I'2... I'T; S3, calculating to obtain a calibration matrix C according to the T groups of linearly independent port excitations I1, I2... IT and the T groups of aperture field excitations I'1,I'2... I'T, wherein I't=C*It exists for the corresponding port excitations It and aperture field excitations I't of any group; And S4, calibrating each array element of the array antenna according tothe calibration matrix C. According to the invention, the array antenna can be quickly and efficiently calibrated through less measurement data in combination with known priori knowledge of the arrayantenna. Compared with the existing calibration method, the method provided by the invention has the advantages of less measurement data, high efficiency, simple system composition, easy engineeringrealization and low cost.

The invention provides a a multi-channel SAR (Synthetic Aperture Radar) antenna performance detection method based on wireless single Transmitter and Receiver calibration. The objective of the invention is to verify the influence of a satellite SAR antenna on the performance change of a multi-channel SAR antenna before and after long-distance transportation and vibration tests. According to the method, the satellite transition test cost and the technical risk possibly caused by folding and unfolding of the antenna are greatly reduced, the SAR antenna performance after transportation and vibration tests is simply and quickly detected; meanwhile, compared with a traditional directional diagram repeated detection method, a novel multi-channel SAR antenna detection method is provided, and thedetection efficiency is improved.

The invention discloses an anti-interference zero setting system, and belongs to the technical field of signal processing. The system comprises an antenna radiation unit, a receiving link, a digital array module and an adaptive beam forming module, wherein a spatial incoming wave signal is received by the antenna radiation unit, amplified and filtered by the receiving link and then sent to the digital array module to complete primary digital beam forming of multiple signals in a subarray, and finally, the adaptive beam forming module forms a zero setting beam and a static beam. According to the invention, through the dimension reduction two-stage beam forming architecture, the calculation amount of beam forming and the adaptive zero setting requirement are both considered. Besides, the optimized non-uniform subarray and layout arrangement are used, so that the sidelobe performance of a directional diagram is improved, and the grating lobe influence of zero-setting beam forming is reduced. The method can be realized on the basis of FPGA and SoC pipeline iterative loop architecture, so that the calculation amount of adaptive zero setting can be further reduced, and the real-time performance of interference signal detection is improved.

The invention discloses an MIMO radar sparse array optimization method based on an MODE algorithm, and relates to the technical field of radar imaging systems. The method comprises two steps to complete sparse array optimization. On the basis of completing the establishment of a covariance matrix, problem modeling is carried out mainly for sparse array optimization. According to the method, a CA+CA+DE algorithm is used for solving a single-objective optimization problem, then single-objective optimization is used as a constraint condition of the optimization, then the single-objective optimization problem is converted into a multi-objective optimization problem, and finally a multi-objective MODE optimization algorithm is used for solving to obtain a sparse array which meets directional diagram matching and inhibits side lobes. The method can converge to global optimization under the condition that the directional diagram is fixed, and the convergence speed is high.

The invention discloses a bidirectional beamforming leaky-wave antenna and a power divider loaded antenna assembly. SIW LWA units with symmetrical double beams are adopted for arraying, the length of the gap of the aperture surface of each unit is designed to meet binomial distribution, and the gap widths of the two units are different, and a substrate integrated waveguide side wall opening with a stop band self-suppression function is designed; the larger the local inductance needs to be reduced, the larger the opening of the side wall of the corresponding substrate is; the Z-shaped anti-phase unequal power divider is used for providing two paths of excitation sources of which the phase difference is 180 degrees and the power ratio is 1: 5. According to the leaky-wave antenna provided by the invention, bilateral beamforming of cosecant square distribution of a radiation pattern in a one-dimensional direction is realized, and the current situation that the conventional SIW LWA only performs cosecant square beamforming on a single side is broken; the technical problem that the open stop band and the sub-directional diagrams cannot be superposed in the same phase is solved.

The invention discloses a beam forming method based on multi-point accurate control. The specific implementation mode of the method comprises the following steps: marking the current weight vector ofa phased array as Wk, pi, calculating the updating step length mu k + 1, m of the weight vector, and updating the weight vector Wk + 1, m, so that the current directional diagram level vector is equalto the expected directional diagram level vector under the current cycle; and defining a steering vector matrix A (theta0, thetak + 1, m), performing singular value decomposition on the A (theta0, thetak + 1, m) to obtain a current cyclic U matrix and an H matrix, calculating a weight vector Wk + 1, pi according to the parameters, completing circulation and iteration, and outputting the weight vector Wk, pi to realize beamforming. According to the implementation mode, beam forming is achieved through the array antenna, few times of iteration can be conducted on the initial weight vector, theexpected directional diagram level vector can be obtained, the antenna directional diagram level vectors in multiple directions can be accurately controlled at the same time in the iteration process,and the implementation process is efficient and accurate. The method has the capability of accurately controlling the main lobe and the side lobe of the antenna pattern, and improves the flexibility of the system.

The invention belongs to the technical field of a broad-angle scanning phased-array antenna, and discloses a broad-angle scanning phased-array antenna adopting a special directional diagram array element, and a design method. A low-profile phased array adopts sub arrays with special directional diagrams as the array element to enable a low-profile phased-array antenna to realize stable gain withina broad scanning angle range or to satisfy the requirement of higher gain with a large scanning angle; the maximum gain directions of the special directional diagram are symmetrically distributed between the normal direction of the array plane and the maximum scanning angle direction close to the maximum scanning angle direction so as to form the characteristic of a concave center of the directional diagram; the central concave depth of the array element directional diagram is designed according to the array group requirement; and the array factor directivity is stronger, the central concaveis deeper. Stable gain of the low-profile phased-array antenna in the broad scanning angel range can be realized or the requirement of higher gain with a large scanning angle can be satisfied under the premise of not changing the phased array factors.

The invention discloses a novel broadband three-dimensional imaging sonar sparse arraying method. The method comprises the steps of initializing preset parameters of a three-dimensional imaging sonar system array; calculating a Fermat spiral array arrangement constant according to the preset parameters; calculating the position of a transducer in a Fermat spiral array structure according to the preset parameters and the Fermat spiral array arrangement constant; replacing a transducer positioned in the inner circle of the three-dimensional imaging sonar Fermat spiral structure with a sound signal emission source transducer; resetting the preset parameters and determining a Fermat spiral ring surface sparse matrix according to the reset preset parameters; and converting the Fermat spiral ring surface sparse matrix into a Cartesian coordinate system. By using the method, the beam forming directivity diagram of the three-dimensional imaging sonar system is ensured to meet the use requirements, and the problems of high hardware consumption and large real-time calculation amount of the existing three-dimensional imaging sonar system are effectively solved. As a novel broadband three-dimensional imaging sonar sparse arraying method, the method can be applied to the technical field of underwater three-dimensional imaging sonar.

The loudspeaker enclosure (10) comprises a central channel (16) turned toward the listener, and left and right side channels (18L, 18R) oriented perpendicular to each other. The signal to be reproduced is separated into: i) a mono component correlated between the left and right signals; ii) left and right surround components decorrelated between the left and right signals; iii) a left component decorrelated between the mono component ant the left signal; and iv) a right component decorrelated between the mono component ant the right signal. The central channel and the side channels are piloted by combinations of these components according to a distribution that is a function of the mode of use of the loudspeaker enclosure, alone in front of a listener and as a pair in association with another similar loudspeaker enclosure, the two loudspeaker enclosures being arranged on the left and on the right of the listener. The directivity diagram is thus modified to create therein directions of cancellation of the stereo image without deformation of the signal rendered.

Disclosed are a metasurface-based random waveform generator and a setting method. A metasurface unit with simultaneous amplitude and phase regulation capability is set, wherein the amplitude regulation depends on adjustment of the rotation angle of a unit, while the phase modulation depends on change of the size of the unit; the phase and amplitude distribution of the metasurface is optimized through a genetic algorithm, so that a target directional diagram is formed in a far field; a Vivaldi antenna is used for irradiating the metasurface, and the amplitude and phase distribution interceptedon the surface are combined, and the amplitude and phase distribution required to be compensated for generating the target far-field directional diagram are calculated; and according to the above steps, a sector-shaped wave generator is arranged. The analysis result shows that a display device can form a very high sector-shaped far-field directional diagram in the range of 9.5 to 10.5GHz.

An antenna directional diagram test method and equipment, an antenna and a storage medium, the method comprising: acquiring echo data generated by the antenna emitting electromagnetic waves to a target scene, the target scene comprising a rotating reflector device (S301); determining target echo data corresponding to the rotating reflector device according to the echo data (S302); and determininga directional diagram of the antenna according to the target echo data (S303). The method can reduce the dependence of the antenna directional diagram on the test environment and the research and development cost, and improve the test effect.

The invention discloses a compact type wideband dual-polarized omnidirectional antenna, which comprises an inverted-cone monopole antenna and a cross bow-tie antenna, wherein the inverted-cone monopole antenna realizes vertical polarization and the cross bow-tie antenna realizes horizontal polarization, the inverted-cone monopole antenna is fed by means of an SMA connecter, and the cross bow-tie antenna is fed by means of a wideband feeding network; the vertical polarization and horizontal polarization are combined by means of a piece of circular metal; and the cross bow-tie antenna serves asa radiator as well as a floor of the inverted-cone monopole antenna, thereby reducing the size of the antenna. The compact type wideband dual-polarized omnidirectional antenna has a bandwidth of about44% and isolation being at least 19 dB, and has a good omnidirectional directivity diagram in the full spectrum band.

The invention provides a beam forming method combined with an antenna array element directional diagram. By utilizing the beam forming method, the performance when the directional diagrams of beam forming array antenna units are inconsistent can be enhanced. According to the technical scheme, the method comprises the following steps: for an array antenna, carrying out directional diagram test on each antenna unit of the array antenna, and establishing an array antenna directional diagram database according to an antenna test point directional diagram; obtaining a fine directional diagram responded by the array antenna in a direction with a higher discretization degree by utilizing an antenna directional diagram database and adopting an interpolation mode of linear interpolation and splineinterpolation; carrying out interpolation on an actually measured antenna directional diagram to obtain a finer directional diagram of the array antenna, utilizing the antenna directional diagram to correct a guide vector of an ideal array antenna, wherein the correction method comprises the following steps: carrying out Hadamard product on the fine directional diagram obtained by interpolation and the guide vector of the ideal array antenna to obtain a corrected guide vector; and then obtaining a beam forming weight vector by using algorithms such as a linear constraint minimum variance LCMVand the like.