Cellular handsets antenna modeling by vector finite element method

Abstract

233 1 INTRODUCION Analysis and design of complicated microwave devices are now impossible without using computer codes for simulation high frequency electromagnetic fields. A number of commercial electromagnetic simu lation codes based on various numerical methods were developed and are now successively used. But the prob lem cannot be considered as completely solved because requirements to simulation instruments become more and more severe together with increasing complexity of microwave systems. In particular, to model electromag netic fields of cellular handsets containing hundreds of parts one have to solve problems of saving computations cost and developing mesh generators insensitive to inev itable errors of geometrical models imported from the CAD systems. Not the least of the factors is high cost of the commercial codes licenses limiting its wide spread. So the problem of developing new computer codes for high frequency electromagnetic field simulation remains sufficiently urgent.In this article an algorithm and a computer code for analysis and optimization of microwave systems based on vector finite element method (VFEM) [1, 2] is described. The VFEM is one of the most universal and powerful methods of numerical solution of mathemat ical physics equations. The method is implemented in frequency domain supposing that every value, describ ing the electromagnetic field, varies with time accord ing to harmonic law:where -complex amplitude (phasor), -angular frequency of field variation, i imaginary unit. 1 The article was translated by the authors.( )In spite of existence of various possible formula tions, the VFEM includes following main steps:1. Formulation of problem equations and boundary conditions.2. Dividing the computational domain on subdo mains-finite elements, compactly covering the domain.3. Discretization of the problem by Ritz or BubnovGalerkin methods, i.e. transition from functional equa tions to a system of linear algebraic equation (SLAE).4. Solution of the SLAE by one of the numerical methods.5. Calculation and visualization fields and parame ters of the analyzed system.These steps are considered more thoroughly in the next sections of the article. Examples of simulation which make possible to estimate efficiency of the pro posed algorithms are also presented. BASIC EQUATIONConsider space domain (region) V, surrounded by a closed surface S where electromagnetic field has to be found, i. e. internal electromagnetic problem has to be solved. A medium in V is supposed to be linear. Electrical field strength in the region satisfies the second order equation, derived from Maxwell's equa tions:(1)where -external electric current density, ε r , μ rrelative permittivity and permeability of the medium, E ( ) ELECTRODYNAMICS AND WAVE PROPAGATIONAbstract-An algorithm of electromagnetic fields simulation and calculation of cellular handsets antenna parameters by vector finite element method in frequency domain is presented. The algorithm is based on dis cretization of the electric field equation by Ga...

Computer Simulation of High‐Frequency Electromagnetic Fields

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Problems of Amplifier Klystron Advancing into the Terahertz Band

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