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The new implementation of max-ortho bases in a method for analysis of axially symmetric antennas is examined from the aspect of analysis-time requirements and average number of integration points per system matrix element. Results for a thick dipole antenna show that for the same number of unknowns, expansion orders up to 64 require fewer resources than lower order bases (i.e. 1st and 2nd order).
This paper presents a novel method for evaluating potential and impedance integrals appearing in the method of moment analysis of arbitrary axially symmetric metallic structures based on exact wire kernel and higher order bases. Due to new variable transforms proposed for singularity cancellation and smoothing the integrands, high accuracy up to machine precision is achieved using relatively small...
Calculation of shielding efficiency of a conducting spherical shell using MoM SIE based code is presented in this paper. Theorem of surface equivalence is used in order to minimize propagation of numerical error through the walls of the shell. Accuracy is further improved by using advanced matrix equilibration and special integration methods for highly accurate evaluation of MoM matrix elements. Simulation...
The paper presents short history of research, development, and usage of higher order basis functions (HOBFs) in thin-wire and boundary element analysis, which are related to application of method of moments (MoM) to surface integral equations (SIEs). Typical example showing advantages of HOBFs is presented. Challenges for HOBFs are outlined.
The paper presents a method for the efficient full wave analysis of electrically large transparent radomes. MoM SIE based code is used for the analyses and the special technique is used for reduction of number of unknown coefficients. Namely, only the part of the radome which is illuminated by main and significant side lobes is taken into account, while remaining parts are excluded from the analysis...
Various methods for numerical calculation of impedance integrals in thin-wire analysis are investigated. Two integration methods based on singularity extraction techniques and one based on singularity cancellation technique are considered for calculation of potential integrals. Five novel transformations for the singularity cancellation technique are compared for the second integration in evaluation...
We present results for simulations of electromagnetic field propagation at 900 MHz in the presence of groups of people. The starting geometry of humans is modeled using combination of programs MakeHuman and Blender. It is then imported into 3-D electromagnetic numerical solver based on surface integral-equation formulation, higher-order basis functions and Galerkin testing, accelerated using graphical...
Analysis of the accuracy of EM simulations of antenna arrays and arrays in vicinity of complex structures, where array elements are modeled by using far field sources, is presented in this paper. Antenna arrays with strong mutual coupling between the elements are the main problem under consideration. It is shown that if the antenna elements are minimum scattering antennas fed by current generators,...
A simple technique for evaluation of bistatic radar cross-section (RCS) is presented. The technique is purely algebraic and it can be applied to any system of equations obtained by the Method of moments (MoM). Since the MoM matrix need not to be inverted and stored, as with the standard MoM approach, one can expect lowering computational costs. Numerical examples are given, with comparison of bistatic...
Standard WIPL-D Pro 3D EM solver is based on higher order Method of Moment (MoM) solution of Surface Integral Equations (SIEs). Using patches of maximum size of 2λ the number of unknowns needed per λ2 of the boundary surface area is reduced down to 25 (50) for metallic (dielectric structures). Owing to parallelization and usage of GPU cards the maximum solvable problem in one day is limited to a boundary...
We outline an approach for full 3-D electromagnetic analysis of stochastically generated trees. It starts from the stochastic model of trees assembled of cylinders with circular cross-section of different radii followed by processing that model in CAD tool, specifically tailored and coded for all-quad meshing. The final closed-surface dielectric model is simulated using a desktop computer equipped...
A simple methodology for the estimation of mutual coupling in antenna arrays which consist of minimum scattering antennas is presented in this paper. The method is based on full 3-D analysis of an element of analyzed array and post-processing of obtained results for input impedance, radiation pattern and electromagnetic field on position of other antennas of the array. Validation is performed by comparing...
We present results for simulations of electromagnetic field propagation in the presence of human crowds in open area. The polarization of the considered incident field is horizontal and vertical, and the operating frequencies are 900 MHz and 1.8 GHz. For the simulations we use 3-D electromagnetic solver based on surface integral-equation formulation, higher-order basis functions and Galerkin testing,...
We present an approach for modeling of human bodies in crowds for the analysis of channel parameters in wireless body area networks. The approach uses distributed surface impedances with method of moments based on surface integral-equation formulation. It significantly reduced the computer resources needed for the electromagnetic analysis, and keeps the final results accurate in a statistical sense.
We outline an implementation of out-of-core direct solver for method of moments-based electromagnetic code. It is designed and executed on a computer cluster where each node has one or more graphical processing units. The algorithm employs simultaneously multi-node parallelism of a cluster architecture and multi-processor parallelism of graphical processing units. This accelerates the overall analysis...
A new analytical-numerical method based on singularity extraction is presented for efficient and accurate evaluation of one of the reflected Sommerfeld integrals over a multilayered media backed by a conducting (PEC) plane. Method is based on extraction of all the poles of the integrand. The method is demonstrated on one element of the tensor multilayered Green's function, where only the singular...
Reflected Sommerfeld integrals over a half-space or over a multilayered media are semi-infinite and for small heights of source and field points tend to converge slow. For improving the convergence, slowly converging terms can be asymptotically extracted, and analytically integrated. In this paper, by the use of one of the analytically solvable Bessel function integrals, a new integrand term is extracted...
Electromagnetic analysis of antennas on electrically large platforms using numerically exact method of moments (MoM) is enormous burden for a personal computer (PC). In this paper we present novel method which converges toward MoM solution, trough the iterative procedure, without dealing with inversion of large matrices, characteristic for MoM.
We present results for comparison of scattered electromagnetic field obtained using numerical analysis of cylindrical and electrically long 3-D structures and 2-D structures of the same cross-section (considered infinite in the third dimension). The parameters of materials of which the structures are made are frequency-dependent. The comparison is done both in frequency-domain and in time-domain....
We quantify the discrepancy between radar cross section (RCS) of long cylindrical scatterers and RCS of infinite structure with the same cross-section. The scatterers are made of perfect electric conductor and are excited so that vector of electric field is perpendicular to the cylinder axis. We use method of moments (MoM) for numerical analysis. The results show that if the cylinder is longer than...
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