Efficient Electromagnetic Models for Systems and Processes of Microwave Heating

The paper examines the modern electromagnetic software available in the market (Multiphysics by ANSYS, QuickWave-3D by QWED, EMC2000-VF by Matra Systemes & Information, Microwave Studio by CST, and some others) with respect to their applicability to the typical problems of microwave power engineering. The solutions to the especially designed benchmark problem (2.45 GHz microwave oven) obtained by some of these codes are considered. The analysis leads to the conclusion that the studied program are adjusted differently for the practical needs of the field whereas models created with the use of the conformal FDTD solver QuickWave-3D ver. 2.0 appear to be quite adequate and beneficial for engineers. The presented examples of simulations of systems of microwave heating and their elements (180 E-plane waveguide bend and packaged food samples in a standard oven) include S-parameters, coupling, distributions of the electric field, and patterns of the dissipated power and SAR. The regime of operating the QuickWave-3D’s solver with modification of media parameters as a function of dissipated power is also illustrated. INTRODUCTION The continuous increase in the quality of modeling and the decrease in the costs of software and hardware have caused a substantial growth of the use of advanced computer simulations in designing wireless telecommunication equipment, computer systems, networking and other products. Engineers and practitioners dealing with non-communication microwave (MW) applications have also become more interested in modeling, however, for most, this arena remains new and unexplored. Recently, the database of the electromagnetic (EM) codes available in the market and applicable to the problems of microwave heating has been created [1]. (The selection criteria for this database were set up to identify the solvers able (as a minimum) to determine return losses and coupling and compute and visualize patterns of dissipated power.) As of today (June 2001), the updated list includes 17 codes (see Figure 1) produced by 16 vendors (see [1] for their names and the web sites). As for the kernel computational methods, Finite Eelment Method and Finite Difference Time Domain (FDTD) prevail, but Method of Moments and Transmission Line Method traditionally considered less powerful and flexible are also available. All the solvers were originally developed for communication applications; their current status in the microwave power engineering can be described by the ratio “Actual” (a code has been used at least once in some R&D or industrial MW power project) over “Potential” (all capabilities outlined in the selection criteria are available); now this ratio is equal to 8/9. The purpose of the present paper is to provide more specific data on some of those codes and their features to help engineers choose the one most suitable for their practical needs.