115 results about "Directivity diagram" patented technology

The invention discloses a directional diagram reconfigurable antenna capable of switching feed through an MEMS switch, and belongs to the field of radio frequency front-end devices. The directional diagram reconfigurable antenna is composed of a micro-strip radiation unit, a guide parasitic unit, a composite beam ohmic contact type MEMS switch, a one-to-four feed network, a direct current bias line, a test patch bonding pad, a coplanar waveguide, a gradual change micro-strip line, a dielectric substrate and a metal ground backboard. The two-stage MEMS switches are erected on the one-to-four feed network, when the two-stage switches on a certain feeder line are turned on, radio frequency current can flow to the corresponding basic radiation unit through the feeder line to generate an inclined beam facing the quadrant, and the two basic radiation units on the front side can be enabled by simultaneously turning on the four switches on the front side to generate an inclined beam facing the quadrant. And generating an inclined beam in the front side positive direction. The antenna adopts a single-layer board design, the dielectric substrate does not need to be punched, the structure is simple, manufacturing is convenient, the adopted MEMS switch is small in loss and high in isolation degree, and rapid printing and manufacturing can be achieved through the surface etching process.

The invention discloses an array antenna phase-only real-time beam scanning and side lobe control method based on machine learning. Firstly, array geometry, scanning angles and minor lobe indexes are set; and then, array element excitation phases meeting requirements are rapidly synthesized by using a phase-only fast Fourier FFT (Fast Fourier Transform) algorithm. Constructing a training data set by taking the scanning angle and the minor lobe index as input and the corresponding phase distribution as output; training a neural network by using the data set to obtain a real-time prediction model from initial excitation distribution to accurate excitation distribution; and according to a target expected directional diagram scanning angle and a sidelobe feature, inputting the scanning angle and the sidelobe feature into a neural network to predict and obtain an array element excitation phase so as to realize a real-time phase-only beam and sidelobe control function. Input dimensions are reduced by extracting key features of a directional diagram, data generation is accelerated by means of FFT, real-time performance and precision are both considered, and the method is suitable for fast beam scheduling tasks of various array antennas.

The invention discloses an intelligent metasurface-assisted phased array transmitting beam directional diagram accurate control method. An intelligent metasurface RIS is introduced into a phased array transmitting system, and an additional signal propagation path is added for transmitting beam forming by utilizing the characteristic that the RIS can freely regulate and control a reflected signal, so that an additional system degree of freedom is obtained. Specifically, a difference value between a minimum peak side lobe power and a minimum main lobe power of a transmitted beam is taken as a target function, and under phase-only transmission weight constraint, main lobe ripple constraint and RIS constant modulus constraint, an alternating direction penalty method is utilized to carry out joint design on a phase-only transmission weight and RIS phase shift. In the iterative solution of the alternating direction penalty method, the subproblem with the constant modulus constraint is solved by adopting a backtracking projection gradient descent method. The method provided by the invention can generate smaller main lobe ripples and lower peak side lobe level, and has better accurate control performance of a beam directional diagram.

The embodiment of the invention provides an edge detection method and device based on gradient weighted fusion and an adaptive threshold, and is applied to the field of computer vision and digital image processing. The method comprises the steps of firstly preprocessing an input image, then extracting two groups of gradient magnitude diagrams and directional diagrams through an adaptive morphological operator and a traditional difference operator, and constructing a weighted fusion function according to the gradient direction consistency of each pixel point to obtain a fused gradient magnitude diagram; and adaptively determining a high threshold and a low threshold based on an information entropy maximization principle, executing an improved Canny process by combining the fused gradient magnitude diagram and the second gradient directional diagram to obtain an initial edge diagram, and outputting a final edge detection result after dynamic structure element optimization. In this way, the defects that in a traditional edge detection method, gradient information extraction is not precise, threshold selection lacks adaptability, and an edge result is fractured can be overcome, more robust and more accurate image edge detection is achieved, and the reliability of an edge detection algorithm in a complex image scene is improved.

The invention discloses a monopole directional diagram reconfigurable antenna based on RF MEMS switch control, and belongs to the field of radio frequency front-end devices. The antenna is composed of a monopole radiation unit, parasitic units located on the left side and the right side of the monopole radiation unit, a composite beam ohmic contact type MEMS switch, a direct current bias line, a test patch bonding pad, a coplanar waveguide, a gradient microstrip line, a dielectric substrate and a metal ground backboard. When the MEMS switch on the parasitic unit is switched on, the length of the parasitic unit is slightly smaller than that of the monopole radiation unit, and the parasitic unit plays a role of a director. When the MEMS switch is turned off, the first-stage leading unit is divided into two parts from the fracture, the length of the first-stage leading unit is far smaller than that of the monopole radiation unit, and backflow is generated by the open circuit of the terminal, so that the effect of reducing and offsetting the second-stage leading unit is achieved. When the switch on one side is pulled down, a directional diagram generates beam deflection towards the side where the switch is closed, the adjustable deflection angle can reach 41 degrees, the gain can reach 6.14 dB, the beam width is about 90 degrees, when the switches on the two sides are both switched off, the beam deflection is 0 degree, the directional diagram points to the positive Z axis, and the gain is 5.15 dB.

The invention discloses a millimeter wave polarization and directional diagram reconfigurable antenna, and belongs to the field of radio frequency front-end devices. The antenna is composed of symmetrical rectangular radiation patches, and a semicircular defect, a quarter circle defect, a rectangular branch load, an orthogonal bidirectional feed network, a T-shaped power dividing feed network, a composite beam ohmic contact type MEMS switch, a direct current bias line, a test patch bonding pad, a coplanar waveguide, a gradient matching structure, a dielectric substrate and a metal ground backboard which are located on the radiation patches. When the single-side MEMS switch on the T-shaped power dividing feed network is switched on, energy flows to the radiation unit on the side, and the leftward or rightward wave beam inclination effect can be achieved. When the MEMS on the two sides are both switched on, the radiation pattern points to the Z positive axis, no beam deflection exists, and therefore the pattern reconfigurable function in the left direction, the middle direction and the right direction can be achieved. When a switch on the orthogonal bidirectional feed network is closed, the size of the long line can realize 90-degree phase delay, and two orthogonal degenerate modes are synthesized into a circularly polarized wave to cover a complete half-power beam width.

The invention discloses an accurate directional diagram null control robust airspace anti-interference method, which considers a multi-antenna receiver communication scene with interference signals in different incoming wave directions, and improves the output signal to interference plus noise ratio of a receiving end by controlling a receiving array directional diagram to form accurate null in the direction of an interference angle of arrival. Therefore, robust airspace anti-interference is realized. In order to control the nulling direction of a directional diagram, the nulling control problem of the directional diagram is converted, and then a filtering weight vector form capable of accurately controlling nulling of the directional diagram is obtained by using an orthogonal projection theory. And then establishing an optimization problem to maximize the output signal to interference plus noise ratio on the premise of controlling the null of the directional diagram. And finally, solving the optimization problem to obtain an optimal filtering weight vector capable of controlling the directional diagram to form accurate null at the angle of arrival of the interference signal. The model is complete, the design method is reasonable and effective, and directional diagram nulling can be effectively controlled in a communication scene in which a receiver faces interference in multiple directions so as to effectively suppress interference.

The invention discloses an amplitude-phase deviation measurement method for simulating an active phased array, which comprises the following steps of: calculating amplitude deviation proportions and phase deviation values of all uplinks / all downlinks of a one-dimensional linear array or a one-dimensional conformal array at one time by utilizing an actual measurement complex number transmitting directional diagram / actual measurement complex number receiving directional diagram; and determining the amplitude-phase deviation of the two-dimensional planar array or the two-dimensional conformal array by using the amplitude-phase deviation of all the one-dimensional linear arrays or all the one-dimensional conformal arrays. Compared with an existing amplitude-phase deviation measurement method, the amplitude-phase deviation measurement method has the advantages that calibration of the transmitting directional diagram / receiving directional diagram is a direct calibration method of the transmitting directional diagram / receiving directional diagram, and due to the fact that the actually-measured transmitting directional diagram / actually-measured receiving directional diagram contains the influence of the mutual coupling effect between the antenna units, the amplitude-phase deviation measurement method can be applied to calibration of the transmitting directional diagram / receiving directional diagram. The deviation between the formed transmitting pattern / receiving pattern and the expected transmitting pattern / receiving pattern is small, and the method has the advantages of being short in measurement time, high in measurement efficiency, low in measurement cost and the like.

The invention discloses a microphone array layout optimization method based on IGSA, and belongs to the field of sound source localization. The method comprises the following steps: firstly, constructing a topological structure of a microphone array as a rectangular array; then, the directivity and the directional diagram of the microphone array are adopted to express the performance of the microphone array; constructing a fitness function through the width of a main lobe, the level of a side lobe and the number of microphones; then, on the basis of a genetic algorithm, improving crossover and mutation steps, adopting a hierarchical crossover strategy and a similarity regulation and control mutation strategy, and simultaneously optimizing an array structure by a simulated annealing operator in an interspersed manner; and finally, outputting the optimal microphone array arrangement to meet the requirements of low sidelobe performance and high resolution. The IGSA algorithm is adopted to optimize the microphone array layout, so that more accurate global optimization, faster convergence speed and better multi-target balance are realized, and particularly, the number of microphones and the hardware cost are remarkably reduced while the sound source localization performance is ensured.

Disclosed in the present invention is a microfluidic antenna with a reconfigurable frequency and directivity pattern. The microfluidic reconfigurable antenna consists of six parts, which are a metal floor, a metal radiation patch, a top reflector, a middle dielectric substrate, a coaxial feeder line penetrating the dielectric substrate, and an annular microfluidic channel packaged with a magnetic liquid metal column, respectively. Different modes can be excited by means of manipulating the length of the magnetic liquid metal column in the microfluidic channel, thus realizing the switching between radiation frequency bands; an antenna directivity pattern is reconfigured by means of manipulating the position of the magnetic liquid metal column; the microfluidic antenna involves main beam switching in a total of ten azimuthal planes within three bands of 5.98-6.10 GHz, 6.08-6.23 GHz and 6.85-7.47 GHz, and the maximum gain values in the states of the three bands are 8.5 dB, 7.4 dB and 8.1 dB, respectively; and the front-to-back ratios are 13 dB, 17 dB and 16 dB, respectively. The present invention has the characteristics of a simple structure, easy integration, a good performance, no introduction of extra distortion, low noise, a high-power operation capability and flexible application.

The invention relates to a microstrip patch antenna based on an antipodal double-helix groove, which comprises the antipodal double-helix groove, a patch, a substrate, a grounding plate and a coaxial probe, and is characterized in that the substrate is mounted on the grounding plate, the patch is mounted on the substrate, the antipodal double-helix groove is formed in the patch, and the coaxial probe sequentially penetrates through the grounding plate, the substrate and the patch; the coaxial probe is used for feeding the patch, and a radio frequency electromagnetic field is generated between the patch and the grounding plate. According to the microstrip patch antenna, the antipodal double-spiral grooves are formed, the path length of current flowing through the patch is increased, the resonant frequency of the antenna is reduced to a large extent, meanwhile, the good radiation characteristic is kept, the antenna radiation efficiency is high, the directional diagram is regular, and the electrical size of the microstrip patch antenna is reduced while the high radiation efficiency is kept.

The utility model provides a waveguide antenna structure with a frequency selective surface structure and a waveguide radar, and the structure comprises a waveguide antenna which is provided with a waveguide slot array and a frequency selective surface structure; the waveguide slot array is arranged on the waveguide antenna in a penetrating manner, and the frequency selective surface structures are distributed on the peripheral side of the waveguide antenna; the frequency selective surface structure comprises surface structure units, and the frequency selective surface structure is formed by arranging a plurality of surface structure units. According to the utility model, the frequency selective surface structure absorbs reflection between the top surface of the antenna and the antenna housing and reduces distortion of a directional diagram; surface waves can be reduced, space coupling between the antennas is reduced, and the isolation between the antennas is improved; the beam directivity can be adjusted, and beam performance specific directivity can be shaped.

The invention discloses a radiation and scattering dynamic regulation cylindrical conformal reconfigurable holographic surface antenna, which comprises a radiator and a feed source, and is characterized in that the radiator comprises M * N conformal reconfigurable holographic surface units, each conformal reconfigurable holographic surface unit comprises two dielectric layers and three metal layers, the dielectric layer is composed of a first cylindrical dielectric layer and a second cylindrical dielectric layer which are distributed from top to bottom; the metal layer comprises a holographic surface patch layer of the first metal layer, a metal ground layer of the second metal layer, a copper column layer of the third metal layer and a direct current bias layer from top to bottom; the holographic surface patch layer is H-shaped and comprises two cylindrical rectangular metal patches, and a variable capacitance diode is arranged between the metal patches; the metal ground layer serves as a floor layer of the whole antenna; the copper column layer and the direct current bias layer provide voltage difference for the variable capacitance diode, control interference pattern impedance distribution of the conformal reconfigurable holographic surface unit, and achieve radiation and scattering beam and directional diagram reconstruction.

The invention provides a millimeter wave directional diagram reconfigurable antenna and a reconfigurable method, and belongs to the technical field of wireless communication. A plurality of radiation structures are integrated on the same transmission line structure, and impedance regulation is performed by loading a control element on the antenna structure, so that one radiation structure is in a matched state, and the other radiation structures are in a mismatched state; time-domain reconfigurable collaborative excitation of a single feed structure on a plurality of radiation modes is realized; energy enters from the feed port and is radiated outwards through the radiation structure in the matched state. According to the invention, time-domain reconfigurable collaborative excitation of a single feed structure on a plurality of radiation modes can be realized; a plurality of modes can be freely and flexibly switched; a simple and compact direct-current circuit is provided; the stable radiation characteristic can be realized; the structure is compact, the integration level is high, the occupied space is small, and machining is easy; the antenna has relatively high gain and efficiency and relatively good working bandwidth; and the space coverage rate is relatively high.

The invention discloses a directional diagram sidelobe level optimization method based on a multichannel DBF, and the method comprises the following steps: S1, correspondingly calculating a theoretical Taylor weighting coefficient for a designed antenna array layout; step S2, solidifying the current iterative Taylor weighting coefficient into the phased array seeker to carry out a directional diagram test; s3, according to a test result of the directional diagram after the Taylor weighting coefficient is added, analyzing an antenna array element which causes a sidelobe level after a first sidelobe of the directional diagram to be higher than a first sidelobe level, comprehensively considering the whole antenna array, and optimizing the Taylor weighting coefficient; s4, verifying the optimized Taylor weighting coefficient, and judging whether the optimized Taylor weighting coefficient meets the performance requirements of a product directional diagram or not; if the product pattern performance requirements are met, executing the step S5; otherwise, returning to the step S2, and continuing loop iteration; and S5, solidifying the Taylor weighting coefficient meeting the product requirement into the product. The method is high in flexibility, high in optimization compensation precision and high in universality.

The application discloses a kind of consistency construction and multi-dimensional parameter joint setting method and system of space field of course beacon, it is related to aviation technology field, comprising: constructing the three-dimensional electromagnetic simulation model of course beacon antenna array, the radiation directivity diagram of antenna array and channel field type characteristics are analyzed;Antenna array is installed and checked and precision is reviewed;Determine that the radio frequency performance of full transmission link meets the requirements;According to correct transmission link, adopt the method of phase matching to carry out channel antenna pair phase matching and clearance antenna pair phase matching in turn, so that the phase of the radiation signal of each antenna pair is the same, and the spatial consistency of antenna pair is constructed;Near-field-far-field signal joint test setting is carried out, near-field test data and far-field test data are obtained, channel line, displacement sensitivity and clearance signal are evaluated, combined with simulation model and actual environment, complete multi-dimensional parameter joint setting.The method significantly improves the consistency and excellence of the final combined field pattern of the space field of the course beacon, and reduces the trial-and-error cost and rework times of flight verification.

1. Name of the product of this design: Graphical user interface for displaying notification information of electronic equipment. 2. Purpose of the product of this design: an electronic device. 3. The key design point of this appearance design product lies in the graphical user interface. 4. The picture or photo that best illustrates the key points of the design: Main view of Design 1. 5. Designate Design 1 as the base design. 6. Purpose of the graphical user interface: The graphical user interface can be used for human-computer interaction and to realize the functions of electronic devices, and can be used to display notification information, such as information, photos, control options, calendars, etc. The graphical user interface can be displayed in a three-dimensional environment within the field of view. The design 1 main view, the design 2 main view, and the design 3 main view show three different directions of the graphical user interface. 7. Human-computer interaction methods of graphical user interfaces: Graphical user interfaces can be interacted with by tapping, pressing, sliding or manipulating the graphical user interface, or by capturing the user's eyes, hands and / or voice.

The invention discloses a lens antenna system with a flexibly reconfigurable wave beam, and the system comprises a lens antenna which comprises a target lens and a multi-path receiving and transmitting array arranged on the surface of the target lens; one side of the signal conversion module is connected with the multi-path transceiving array; one side of the digital domain coding module is connected with the other side of the signal conversion module; the target lens is used for adjusting wavefront phases of received and transmitted electromagnetic waves and focusing or parallelizing the received and transmitted electromagnetic waves; the multi-path receiving and transmitting array is used for forming receiving and transmitting directional diagrams in multiple directions through the target lens; the signal conversion module is used for converting signals between the multi-path transceiving array and the digital domain coding module; and the digital domain coding module is used for carrying out digital domain coding processing on the digital domain transmit-receive signal. According to the lens antenna system, the beam forming performance can be improved, meanwhile, flexible reconstruction of the beam is achieved, the anti-interference capacity of the lens antenna system can be improved, and the application scene of the lens antenna system can be expanded.

In order to achieve an object that is to provide a communication control apparatus capable of improving utilization efficiency of frequency bands in communication using beams, the communication control apparatus includes at least one processor, which carries out: a control process of controlling a communication apparatus capable of communicating with a plurality of communication terminals by irradiating the plurality of communication terminals with a radio wave beam from an antenna; an acquisition process of acquiring control information that includes terminal position information indicating positions of the plurality of communication terminals, apparatus position information indicating a position of the communication apparatus, and constraint information including information indicating a physical constraint of the antenna; and a determination process of determining, on the basis of the control information, a directivity pattern of the antenna in generation of the beam, and allocation of a frequency band to the beam.

The invention relates to a satellite-borne synthetic aperture radar in-orbit calibration method and system, and belongs to the technical field of satellite-borne SAR calibration, and the method comprises the steps: selecting a uniform scene target to execute a calibration task after a satellite enters an orbit and before a conventional observation task is executed, and obtaining an initial value of a distance direction beam pointing calibration parameter; in the conventional observation task, a pointing calibration area and a calibration observation period for the pointing calibration area are determined; based on business data of a conventional observation task, calculating a distance directional diagram for observing a pointing calibration area in a calibration observation period; and gradually comparing the observed distance directional diagrams, inverting the distance pointing deviation of the current observation relative to the previous observation, correcting the current distance directional diagram, updating the current distance beam pointing calibration parameters, and ensuring the accuracy of the conventional observation task business data in each calibration observation period. The on-orbit calibration method is efficient and convenient, and the task arrangement frequency is reduced.

The invention relates to the field of traffic planning route optimization, and discloses a traffic route space and passenger flow pattern optimization method and system, and a storage medium. The traffic line space and passenger flow directional diagram optimization method comprises the following steps: acquiring a station position and section passenger flow information of a traffic line in a target area, and generating a space direction division method; reconstructing the traffic line based on the section passenger flow information to obtain a reconstructed line diagram; forming sub-lines by adjacent stations in the reconstructed line diagram, and translating starting points of the sub-lines to the same position to obtain a space directional diagram and a passenger flow directional diagram; according to a space direction division method, respectively grouping the space directional diagram and the passenger flow directional diagram; and calculating the grouped space directional diagram and passenger flow directional diagram based on a preset method to obtain a space directional value and a passenger flow directional value. According to the method, the traffic line space direction and the passenger flow direction can be quantitatively described, the integrity of current traffic description in the region is improved, and subsequent traffic line planning and prediction are served and supported.

The invention discloses an antenna assembly, and relates to the technical field of Internet of Things. The antenna assembly comprises an antenna and a reflecting plate, the reflecting plate is provided with a reflecting surface, the antenna and the reflecting plate are arranged at an interval, the antenna and the reflecting surface are oppositely arranged, and the reflecting surface is used for adjusting an antenna pattern of the antenna. According to the embodiment of the invention, the antenna pattern is adjusted by arranging the reflecting plate with the reflecting surface, an antenna does not need to be customized for each scene, the cost is saved, and the implementation difficulty is low.

The invention discloses a miniaturized double-slot Vivaldi sum-difference beam antenna for target positioning and tracking. The miniaturized double-slot Vivaldi sum-difference beam antenna comprises a double-slot radiation patch, a dielectric substrate and two sum-difference microstrip feed structures, when the phases of the incident signals of the two ports are consistent, a difference beam is generated; and when the difference is 180 degrees, a sum beam is generated. Furthermore, in order to reduce the mutual coupling effect between the two ports, a trapezoidal structure (flow repression groove) is dug out at the most front end of the radiation patch, and a small quadrangular prism is dug out at the corresponding position of the dielectric substrate. Furthermore, the front end part of the dielectric substrate is extended downwards by 0.8 mm and is equivalent to a director, so that the antenna gain is improved. The size of the final antenna is 61 * 48.6 * 1.6 (mm < 3 >), the working bandwidth of the wave beam is 2.85-21GHz, the gain in the frequency band of 6-21GHz is greater than 8dBi, and a directional diagram has high symmetry. The difference beam working bandwidth is 4.35-20.85 GHz, the sidelobe level is low, the anti-interference capability is high, and the directional diagram has high symmetry. The method has great application value in the field of target tracking and positioning.

The invention discloses a ray tracing simulation method fusing a base station microenvironment coupling effect, and the method comprises the implementation steps: scanning a microenvironment of an area where a base station antenna is to be placed through a laser point cloud device, sequentially carrying out the preprocessing and triangular surface element fitting processing of point cloud information obtained through scanning, and obtaining a triangular surface element model of the microenvironment; placing a base station antenna in the triangular surface element model, and setting related parameters; generating a coupling directional diagram of the base station antenna and the microenvironment model by adopting a high-frequency approximation algorithm; and loading a digital elevation map, and calling a ray tracing model by using the coupling directional diagram to obtain a wireless channel prediction result. The problem that a traditional directional diagram changes in an actual scene is solved, errors caused by the fact that the directional diagram does not conform to reality in the wireless channel prediction process are avoided, and the simulation accuracy of the ray tracing model is improved.

The present application relates to the technical field of millimeter wave radar signal processing, in particular to a millimeter wave radar pitch angle ambiguity discrimination method based on directional diagram features and machine learning, and the specific steps are as follows: S1, channel response directional diagram data collection; S2, training data generation; S3, data enhancement processing; S4, feature data preprocessing; S5, model training and optimization; S6, model verification and evaluation; S7, ambiguity discrimination and confidence output; In the complex environment and multi-target scene, unlike the traditional method, the shortcomings of the prior art are overcome, the directional diagram features are introduced, the radar hardware channel characteristics are fully utilized, the channel response directional diagram features and the machine learning model are combined, the performance of the pitch angle ambiguity discrimination is improved, the feature extraction and model inference calculation amount are small, and the real-time processing requirements of the radar are met.

The invention discloses a compact ultra-wide-angle scanning antenna array based on an adjustable unit directional diagram. Based on the superposition principle of dipole and monopole directional diagrams included in the antenna unit, unit directional diagram deflection is realized, and unit gain at an unexpected angle is reduced. Based on unit pattern deflection, array large scanning angle gain is improved, and wide-angle scanning can be realized; due to the fact that the unexpected angle unit gain is low, array low sidelobe scanning can be achieved. According to the invention, the unit structure is compact, the feed structure is simple, and the side lobe level of the array at a large scanning angle is significantly reduced while the wide-angle scanning capability is achieved.

The invention discloses an irregular subarray division design method for a low-sidelobe wide-angle scanning array antenna, and solves the problem that the optimization time is long due to the slow speed of calculating the sidelobe level in the prior art. The method comprises the steps of discretizing an array plane into an array element set, performing permutation and combination on array elements in the array element set to obtain a sub-array position combination set, and constructing a dictionary matrix; converting a sub-array division problem into a set coverage problem, solving a binary selection vector to enable the dictionary matrix and the binary selection vector to obtain a whole-row vector, and further obtaining a candidate sub-array combination set of a coverage array surface; constructing an irregular subarray division design model, and screening the candidate subarray combination set to obtain an optimal subarray division result; optimizing the excitation amplitude of the optimal sub-array division result by using the optimal sub-array division result and adopting a grey wolf optimization algorithm so as to reduce the sidelobe level of the directional diagram; according to the method, direct calculation of the sidelobe level is replaced, so that the calculation efficiency is improved.

The present invention discloses a dual-frequency four-arm helical antenna for low-orbit satellite communication, including a direct-feed helical unit, a coupled-feed helical unit, an antenna reflective base plate and a feeding network; the tops of the direct-feed helical unit and the coupled-feed helical unit are open-circuited and installed on the antenna reflective base plate in a coaxial nested manner; the coupled-feed helical unit is connected to the grounding point of the coupled-feed helical arm; the direct-feed helical unit is connected to the feeding point of the direct-feed helical arm; the feeding network is installed on the antenna reflective base plate, connected to multiple direct-feed helical arm feeding points, and is used to feed multiple direct-feed helical arms. The present invention simultaneously satisfies the dual-band operation of the four-arm helical antenna, and both dual-bands have approximately the same heart-shaped radiation pattern, so that the low-orbit satellite can have the best effect in both receiving and transmitting when communicating at a low elevation angle of the terminal.

The application discloses a sum and difference beam optimization method of a cover array antenna, and comprises the following steps: creating an array antenna model and a cover array antenna model; performing quadrilateral mesh division on the models respectively; based on the corresponding quadrilateral mesh division of the models, performing simulation calculation by using a high-order moment method, and extracting corresponding active unit directional diagrams; applying excitation to the antenna units in the models, combining the active unit directional diagrams, calculating the sum and difference beams of the models under different scanning angles, and comparing corresponding performance indexes; and using an improved hybrid differential evolution algorithm to optimize the sum and difference beams of the cover array antenna model which does not meet the index requirements; wherein the improved hybrid differential evolution algorithm performs global and local iterative searches, and adaptively calculates a mutation factor and a crossover factor in the global and local iterative search processes. The application realizes the optimization design of the sum and difference beams of the cover array antenna, and is more in line with engineering application requirements.

The invention discloses a quick correction method for a phase value of a phased beam scanning wave control table, which belongs to the array antenna technology, and is characterized in that a homogenized directional diagram of an antenna unit in an array provided by the invention is calculated only through full-wave simulation or test of an individual beam position of an antipode; on the basis, the phase correction value of each beam position in the beam control table can be quickly obtained, and the purpose of quickly correcting the array beam pointing deviation is achieved. According to the method for rapidly correcting the phase value of the phased beam scanning wave control table, mutual coupling between antenna units in an array does not need to be specially researched, full-wave simulation or debugging testing does not need to be carried out on beam positions of the whole array one by one, the method can be implemented in a design stage and a verification test stage, and the method is high in practicability. The method has the advantages of high correction precision, high speed, wide applicability, easiness in implementation, low cost and the like.