512 results about "Electromagnetic simulation" patented technology

The invention discloses a high-efficiency time domain electromagnetic simulation method based on an H matrix algorithm, which can realize electromagnetic simulation on a large three-dimensional target. In the method, a time domain finite element method (TDFEM) is used as a background, a low-rank compression technique is used as a core, and a tree structure is used as a basis for carrying out logical unit (LU) decomposition on a sparse matrix generated by the TDFEM by a four arithmetic algorithm corresponding to the H matrix. The acquired upper and lower triangular factors have low-rank compressible characteristics, and the compressed matrix equation can realize quick solution of high-efficiency time domain electromagnetic simulation by the H matrix algorithm. The high-efficiency time domain electromagnetic simulation method has the advantages of fast computation speed, low memory consumption, controllable computation accuracy, good stability and the like, can reduce the complexity of computation to O(Nlog<2>N) and reduce the memory consumption to O(NlogN), can be widely applied to the solution of a large sparse linear system of equations during high-efficiency time domain electromagnetic simulation, and can provide important reference for analyzing the electromagnetic property of the large three-dimensional target.

The invention relates to a bicircular polarized broad-band antenna radiating element used for a large-angle scanning phased array, which comprises a waveguide shell, a left-handed circular polarized input port, a right-handed circular polarized input port, a circular polarized membrane, packing media, a choke groove and an impedance matching dielectric layer, wherein the left-handed circular polarized input port and the right-handed circular polarized input port are symmetrical structures; the circular polarized membrane is arranged on the axle wire of the waveguide shell; after a linearly polarized signal input by the left-handed circular polarized input port or the right-handed circular polarized input port is converted into a circular polarized signal by the circular polarized membrane and after impedance matching is carried out on the circular polarized signal by the choke groove and the impedance matching dielectric layer, left-handed or right-handed circular polarized electromagnetic waves are externally radiated. The thickness of the impedance matching dielectric layer, the thickness and the radius of the choke groove and the distance between the choke groove and the impedance matching dielectric layer are optimized by electromagnetic simulation, and thereby, scanning dead zones can not be generated definitely under the condition of large-angle scanning.

The invention relates to a nano-brick array holographic sheet applied to holographic anti-counterfeiting and a design method for the nano-brick array holographic sheet. Nano-brick array units in periodical arrangement are etched in the working surface of a substrate, a resonance-based reflective type working pattern is adopted, and the diffraction distance is 1-10[mu]m; the substrate can be divided into multiple unit structures corresponding to the nano bricks; all the unit structures are the same in lengths, widths and heights, the working surface of a single unit structure is square, and the length of side can be obtained by electromagnetic simulation optimization; in the nano-brick array units, the number of the nano bricks and the number of pixels in target images are equal; and the lengths, widths and heights of all the nano bricks are equal, and the orientation angles are designed according to phase distribution. According to the nano-brick array holographic sheet, redundant diffraction levels are omitted, good imaging quality and high efficiency are realized, and the energy is completely refracted basically; and compared with the conventional surface embossment type and refractive index type phase hologram, the nano-brick array holographic sheet has the advantages of small size, high integration, light weight, batch copying and the like, and can be widely applied to the aspects of laser trademarks, holographic anti-counterfeiting and the like.

The invention discloses an electromagnetic-simulation-based evaluation method for an unmanned plane planning route. The method comprises the following steps: step one, carrying out virtual test flight field system construction and field configuration; step two, driving an unmanned plane to carry out simulated flight along a planned route; step three, carrying out simulated calculation of electromagnetic data; step four, carrying out electromagnetic distribution display and route warning recording; and step five, carrying out integrated route evaluation. According to the invention, electromagnetic distribution of the unmanned plane can be displayed visually on the planned route; and a route (segment) lower than a data link electromagnetic signal detection threshold value can be warned and recorded and thus the route (segment) can be evaluated after flight completion.

The invention relates to an electromagnetic condition test method based on simulation data, which builds an electromagnetic simulation numerical model according to a tested object and adopts a prior electromagnetic simulation software to calculate the electromagnetic field distribution at the surface of the object; finds an actual measurement point O and finds the actual electric field intensity E at the point and extracts the predicated data from the simulation data; processes power fitting to attain a fitting equation as E=aR<-b> to describe the change of the field intensity along with distance; adopts the b as the b of a derivation equation as E=aR<-b>, and induces the electric field intensity E of the actual measurement point and the distance between the O point and the V point into the equation to obtain a; induces the distance of the derived point into the equation as E=aR<-b>; and obtain the approximate value of the electric field intensity at the T point. The invention can obtain a predicted value nearly same as the actual test data in the open area of a complex structure, satisfy the test on the electromagnetic condition in actual engineering. The invention can improve test efficiency, protect testers and realize high test accuracy.

The invention discloses a multi-resolution precondition method for analyzing aerial radiation and electromagnetic scattering problems in electromagnetic simulation. The method is a method for generating a multi-resolution basis function by using a geometrical mode on a laminar grid constructed in a grid aggregation mode and further generating multi-resolution preconditions, wherein the multi-resolution basis function is formed by linear combination of a classical vector triangle basis function (RWG), and can be conveniently applied to the conventional moment method electromagnetic simulation program to effectively improve the behavior of a matrix formed in the moment method electromagnetic simulation process so as to realize acceleration of the iterative solution process of a matrix equation and fulfill the purpose of accelerating the moment method electromagnetic simulation process. Meanwhile, the multi-resolution pre-processing technology can also be conveniently combined with a quick algorithm such as a quick multi-pole algorithm. The method has the advantages of short calculation time and capability of ensuring high precision of the program and low demand of a computing memory, and can effectively improve the computing efficiency of the conventional electromagnetic simulation.

The invention relates to an electric control radiation directional diagram reconfigurable antenna. The reconfiguration of the directional diagram of the antenna is finished by the following steps of: (1) selecting the working frequency f of an antenna; (2) confirming an arrangement cycle of an artificial structure material unit in three directions, an antenna integral structure and a metal structure and the substrate material of a formed unit, wherein the arrangement cycle comprises geometric parameters of the substrate material and the metal structure; (3) adding a variode on an opening of the metal structure; (4) calculating the transmission spectrum S21 phase of the unit by utilizing electromagnetic simulation software, continuously changing a capacitance value of the variode, recording the corresponding phase of a scattering parameter and drawing a phase-capacitance C curve; (5) arranging an artificial material along the horizontal plane cycle, dividing the artificial structure material into N areas with equal distance, and controlling a voltage value loaded on the variode in the unused area, wherein all the areas have equal structural size and contain equal amount of units. The antenna is a controllable antenna of a broadband and can realize positive/negative 40-degree deflection or so of a main lobe of the radiation directional diagram of the antenna.

The invention discloses a simulation method of an MMC (modular multilevel converter). The simulation method comprises the following steps: (1) obtaining operation parameters of an SM (Submodule); (2) construction an equivalent circuit of SM; (3) establishing an artificial circuit of SM; and (4) establishing a simulation system of MMC and simulating the system. According to the simulation method provided by the invention, by the utilization of numerical calculation and electromagnetic simulation internal mechanism, the SM in the MMC can be equivalent to a simple branch formed by a controlled voltage source and an adjustable resistor effectively, and the number of nodes of the system and the corresponding simulation calculation can be greatly reduced, so that on the premise that the simulation precision is ensured, the simulation speed of the MMC is greatly promoted, and the method is applied for MMC design.

The invention discloses a system and a method for carrying out well logging by utilizing a transient electromagnetic simulation signal; the system comprises three parts, i.e., a ground acquisition unit, a downhole measurement unit and a cable, wherein a ground power supply module in the ground acquisition unit is used for providing direct current (DC) or alternating current (AC) to a downhole circuit power supply in the downhole measurement unit as well as a ground synchronous processing module, a ground high-precision AD conversion circuit and a ground display storage module; the downhole circuit power supply is used for providing the current to a downhole transient electromagnetic excitation power supply for supplying power (large current) and providing the current to a downhole electronic circuit for supplying power (small current); a downhole transient electromagnetic excitation main power supply is used for providing the current to a power module. According to the system and the method, the resistivity of stratum outside a casing is obtained by continuously measuring the response of a transient electromagnetic field in a cased well, and a stratum resistivity curve needed by evaluation of remaining oil is obtained; the system and the method are not affected by contact, and are easy in construction and high in working efficiency.

The invention provides a method for optimizing a PCB microstrip line structure on the basis of a response surface methodology and a genetic algorithm. The method comprises the steps that an electromagnetic simulation model of a PCB microstrip line is built on the basis of HFSS software; return loss and insertion loss of the microstrip line are obtained on the basis of the model; 29 tests are designed for computing simulation by taking the substrate thickness, the microstrip line width, the microstrip line thickness and the dielectric constant as design parameters and taking the return loss as a target value; the relationship, obtained in the tests under the 5-GHZ condition, between the return loss and the influence factors thereof is fit by adopting the response surface methodology; the obtained fit function is optimized by means of the globally optimal solution searching advantage of the genetic algorithm, and combined parameters with the minimal return loss are obtained. In addition, by means of HFSS simulation verification, the accuracy of an optimization result is proved, and the method has a guiding effect on optimization design of other interconnection structures.

The invention discloses a method for determining the influence on scaling by a high-resolution SAR reference target RCS and a compensation method. The method for determining the influence on scaling by the high-resolution SAR reference target RCS comprises the steps that based on an FEKO three-dimensional electromagnetic simulation result, data of the reference target RCS changing along with frequency bands or azimuth angles are acquired based on a multilevel fast multipole method; afterwards, the reference target RCS is introduced into an SAR echo signal, so the influence on an imaging result by the reference target RCS changing along with the frequency bands or the azimuth angles can be analyzed and estimated comprehensively and quantitatively; accordingly, the method is an analyzing method closer to actual conditions. The compensation method comprises the steps that firstly, existing high-resolution SAR reference target RCS data having different center frequencies and/or frequency band ranges are simulated; secondly, based on the result of the influence on scaling, the maximum value of integral energy difference values in bandwidth which actually uses high-resolution SAR is judged, and whether at least one of the maximum values of integral energy difference values in azimuth beamwidth is greater than or equal to 0.2 dB is judged, so whether echo compensation is performed or not is determined. Accordingly, the computation burden can be reduced while SAR detection accuracy is met.

The invention relates to a high-gain low-side lobe half-height waveguide wide side slot antenna. The antenna comprises the following parts: a shielding plate and a half-height waveguide wide side bias slot. The antenna is designed through a method of the combination of classical electromagnetic theory of waveguide slot and electromagnetic simulation software. The mathematic relation between radiation slot parameters at ideal state and line source aperture distribution is given out according to an Elliot theory, the slot parameters of an antenna are subjected to simulation through the electromagnetic simulation software, and the relation between the radiation slot conductivity and the slot position length is obtained according to simulation data fitting, so that all parameters of the slot are worked out, and a step of experimental debugging is canceled. Finally the shielding plate is designed for the antenna according to the requirements of gain indexes. The array antenna has the characteristics of high gain, low side lobe and low weight, and is applicable to occasions where high-power and high-definition radar antennas are required for ship-navigation radars and sea detection radars.

The invention discloses a fast multi-target antenna design method based on dynamic updating of an agent model. The agent model is utilized for fitting electromagnetic simulation data of an antenna design parameter sample, electromagnetic simulation consuming a long time is replaced for achieving instantaneous approximate calculation from antenna structure parameters to electromagnetic responses, therefore, the electromagnetic response frequency is reduced, and the calculation cost is greatly reduced; meanwhile, the antenna design parameter sample is newly added in the antenna design process for dynamically updating the agent model, so that the prediction precision of the agent model is improved. According to the fast multi-target antenna design method based on dynamic updating of the agent model, the antenna design efficiency is greatly improved, the method is suitable for solving various antenna structure continuous parameter variable design problems and more remarkable in advantage when especially used for solving the complex high-dimensional multi-target antenna design problem.

The invention discloses a medium rough surface finite element electromagnetic simulation method based on integral boundary. The medium rough surface finite element electromagnetic simulation method based on the integral boundary mainly solves the problem that similarity of inhomogeneous media and approximate absorbing boundary are difficult to solve by integral equation class methods. The medium rough surface finite element electromagnetic simulation method based on the integral boundary comprises the achieving steps of using a monte carlo method for obtaining a medium rough surface, carrying out truncation processing and scattering on the medium rough surface through an artificial boundary, acquiring a finite element equation of a simulation area according to a functional method inside the simulation area, using an integral equation method for obtaining integral boundary conditions outside the simulation area, forming an electromagnetic coupled equation through continuous conditions, and finally obtaining radar scattering parameters of the medium rough surface by solving an electromagnetic coupled matrix equation. Compared with the prior art, the medium rough surface finite element electromagnetic simulation method based on the integral boundary can be more easily used for simulating inhomogeneous medium electromagnetic problems than the integral equation class methods, can improve electromagnetic simulation precision compared with the approximate absorbing boundary, and can be used for acquiring the electromagnetic scattering parameters of medium rough surface unbounded area problems.

The invention provides an S parameter de-embedding method of a multiport network. An S parameter of a multiport clamp is obtained, a matrix operation is used to remove the S parameter of the clamp after that the S parameter of the whole clamp is obtained, and a formula is derived in an incident/reflection wave manner during de-embedding. Compared with a present de-embedding method in which electromagnetic simulation is used to calculate the clamp parameter, the method of the invention is higher in precision; and compared with TRL calibration, calibration in the invention is simpler, and calibration pieces are easier to prepare.

The invention discloses a differential evolution algorithm based multi-layer frequency selection surface composite wave-absorbing structure and material optimum design method. The method includes: performing mutation and crossover operations by the aid of the different evolution algorithm; subjecting the composite structure to modeling calculation by the aid of electromagnetic simulation software and feeding back calculated results to a program to complete the operations; searching and generating an optimum model reaching the objective function and optimal structure parameters and material materials in variant fields. By the differential evolution algorithm based multi-layer frequency selection surface composite wave-absorbing structure and material, the model can be optimized in structure parameters, and a new material with the optimal ratio can be obtained through the differential evolution algorithm according to an original absorber and the electromagnetic parameters on the substrate. The optimum design method has the advantages that design cycle is short, and the composite wave-absorbing structure and material low in reflection coefficient, wide in frequency band and thin in thickness can be obtained rapidly.

The invention discloses a design method for a pure medium electromagnetic lens based on a meta-surface. The method includes the following steps that firstly, according to medium materials of the lens and the wavelength of working electromagnetic waves, the relation between phase changes and medium thicknesses is obtained; secondly, according to requirements for the type and focal length of the lens (a convex lens or a concave lens or a reflecting mirror), needed distribution of phase jumps is worked out; thirdly, according to phase distribution requirements, the medium lens with the corresponding thickness is established in electromagnetic simulation software, is simulated and finely adjusted and then can be manufactured, wherein the phase distribution phi is obtained according to the requirement of the lens designed in the second step, distribution of the medium thicknesses is worked out, and modeling and simulating are conducted in the electromagnetic simulation software. The design method is simple and flexible; along with reduction of incidence wavelengths, the focal length of the lens will be increased; a lens set composed of the lens and a traditional lens can eliminate chromatic aberration.

The invention provides an auxiliary debugging method and equipment for microwave filters and storage equipment. The method comprises the following steps of: obtaining a dissipation parameter through changing a bolt length of a microwave filter in electromagnetic simulation software or a screw length of a practical filter, so as to form sample data; extracting a mixed element from the dissipation parameter; obtaining a data set Data between a mixed element feature and the screw length; training the data set to establish a reverse electromechanical characteristic model Dmodel between the mixed element feature and the screw length; and inputting an ideal mixed element designed by a generalized Chebyshev synthetic method into the model to obtain an ideal length of the screw. The auxiliary debugging method and equipment for microwave filters and the storage equipment are used for realizing an auxiliary debugging method for microwave filters. The method provided by the invention is capable of shortening the debugging time and improving the debugging efficiency.

The invention discloses a transmission type artificial electromagnetic surface and a design method thereof. The transmission type artificial electromagnetic surface comprises a medium substrate, a random surface covering an upper surface of the medium substrate, and a frequency selection surface covering a lower surface of the medium substrate, wherein the random surface is an unit array composed of three-different-dimension basic units which are uniformly arranged in a random mode, and the frequency selection surface is a structural array formed by same square ring units having branch knots. The transmission type artificial electromagnetic surface is advantaged in that composite high frequency stealth and low frequency wave permeability functions are realized, and small thickness, light weight and easy processing are realized; the method comprises steps that (1), a traditional random surface design method is employed to design structural dimensions and spatial arrangement of each basic unit forming the random surface; (2), the square ring units having the branch knots are selected to form the frequency selection surface; and (3), basic composite units are constructed, and the structural dimensions of each unit are adjusted through electromagnetic simulation till high wave permeability and X wave band stealth requirements of the low frequency are satisfied.

The invention discloses a method capable of implementing quick electromagnetic simulation of complex layered medium structures, wherein the method is used for efficient simulation of the complex layered medium structures on basis of combination of matrix decomposition and novel singular value decomposition. The method includes: using triangular meshes to precisely simulate a model, and subjecting far-field groups to low-order compact according to the principle of fine low-order characteristics of far-field groups in tree structures to obtain a sparse matrix representation form. The method which is a pure mathematic analytical method is independent of an expansion form of the green function, internal memory and computing time are reduced by the novel singular value compact method based on MDA (matrix decomposition algorithm), the computing complexity can be lowered to O (NlogN), and memory consumption can be lowered to O (NlogN). The method is especially suitable for electromagnetic simulation analysis of complex layered medium structures and can be also used for providing effective means for layered medium structure simulation with the complex green function.

The embodiments of the invention provide an extracting method and system for electromagnetic radiation characteristic parameters of apparatuses and belong to the technical field of electromagnetic compatibility. The method comprises the steps of determining an electromagnetic interference source of an apparatus; calculating a current of an equivalent circuit of a common mode current circuit of the electromagnetic interference source based on the Kirchhoff laws to obtain a common mode interference current of the electromagnetic interference source; placing an equivalent model obtained through equivalent treatment of the common mode interference current into a three-dimensional model of the apparatus to obtain a target apparatus model; performing three-dimensional electromagnetic simulation on the target apparatus model to obtain a three-dimensional electromagnetic simulation result, wherein an excitation source of the three-dimensional electromagnetic simulation is the common mode interference current; extracting the electromagnetic radiation characteristic parameters of the apparatus from the three-dimensional electromagnetic simulation result. The method and the system solve the problem that only the physical properties of systems and apparatuses in airplanes are analyzed and no analysis for electromagnetic radiation characteristics is performed in the prior art, and realize the analysis of electromagnetic radiation characteristics in airplanes and extracting of the electromagnetic radiation characteristic parameters.

The invention discloses a multi-blocking mode-considering full-bridge sub-module MMC-based equivalent simulation method. The method comprises the following steps: obtaining a bridge arm current corresponding to a bridge arm and switching signals of full-bridge sub-modules IGBT of the bridge arm; constructing equivalent circuits of the full-bridge sub-modules according to running parameters; and establishing corresponding simulation systems according to the equivalent circuits of the full-bridge sub-modules and carrying out simulation. According to the MMC equivalent simulation method, the sub-modules are equivalent to Thevenin equivalent branches by utilizing numerical calculation and internal mechanism of electromagnetic simulation, so that the frequent on-off of mass of power electronic devices is avoided and the simulative calculation time is greatly shortened; and meanwhile, real diode devices are introduced to consider diversified blocking manners of the full-bridge sub-modules, so that the blocking states of the full-bridge sub-modules can be accurately simulated under the premise of ensuring the simulation speed.

The invention discloses an optimization method for improving random vibration stress and echo loss of chip package solder joints by unilaterally performing vibration analysis research or unilateral echo loss research. CSP solder joint models are established in ANSYS and HFSS software, the finite element analysis model and three-dimensional electromagnetic simulation analysis of the model are carried out, Response surface method is used to design the horizontal combination of multi-group solder joint morphology parameters and to model for simulation calculation, and the response surface methodis used to calculate the stress value, the relationship between the return loss and the shape parameters of CSP solder joints is fitted, The initial population generation, crossover, mutation and evolutionary inversion were performed on the fitting function respectively, and the two populations were evaluated and updated as a whole. The local catastrophe is performed on the population if the conditions were satisfied, and the random vibration stress value and echo loss value of CSP solder joints were obtained while the parameter level combination is reduced. This method can be used to guide the design of structural parameters which take into account the random vibration stress and return loss of CSP solder joints.

The invention discloses an antenna-shock tube-antenna plasma electromagnetic characteristic simulation method and system. The method comprises: determining dimensions of a shove tube experimental apparatus, electromagnetic parameters of a material used, structure, and experimental conditions; determining the size and structure of a simulation area; determining electromagnetic parameters of the material, and building a three-dimensional electromagnetic simulation model of the simulation area in a program; performing simulating according to the experimental conditions to obtain flow field distribution in a shock tube experimental segment; coupling simulation data of a flow field to meshes of the three-dimensional electromagnetic simulation model to obtain flow field data on the full-space electromagnetic meshes; coupling flow field mesh parameters to electromagnetic mesh parameters; filling the three-dimensional electromagnetic simulation model with the flow field electromagnetic parameters, and running the simulation program to obtain simulation results. A real simulation process is simulated via the program, flow field simulation and electromagnetic simulation are combined, and therefore, plasma interaction of electromagnetic wave with plasma in a shock tube is more truly simulated.

The invention provides a modeling and packaging method for process tolerance and electric performance coupling characteristics in radio frequency integration. The method starts from development and application of process IP models to put forward an integrated scheme which is compatible with existing modeling algorithms and rapidly and correctly realizes model development, integrated packaging andupdating maintenance by utilizing data of electromagnetic simulation combined test, and the integrated scheme is particularly suitable for modeling and simulation of process tolerance and electric performance coupling characteristics in radio frequency microwave integration. According to the method, processing and modeling are carried out on process tolerance data in integrated manufacturing, andmanufacture process levels are truly fed back to designers for calling through a standard IP library form, so that system-level simulation can cover analysis of process tolerance, the simulation is capable of rapidly and effectively verifying influences, on system performance, of the process manufacturing levels, and benefit is brought to shorten the design verification period.