Elliptical applicator design through analysis, modelling and material property knowledge

[摘要] The properties of an elliptical microwave applicator are investigated. The investigationincludes the analytical solution of the cutoff frequencies and electromagnetic fieldpatterns in elliptical waveguides. This requires the solution of Mathieu Functions andbecoming familiar with an orthogonal elliptical coordinate system. The study forms partof a wider investigation into the microwave heating of minerals and a cavity isdesigned in such a way that modes are produced at 896MHz. Extensive use is made ofsimulation packages. These software packages require that the user knows thedielectric properties of materials that are part of simulations. Therefore, thedetermination of these properties through measurement and the use of geneticalgorithms is considered. A method to improve an S-band waveguide measurementsystem by implementing time domain gating and an offline calibration code previouslywritten forms an integral part of this section of the project. It is found that, within limits,elliptical waveguides tend to produce a greater number of modes within a certainfrequency range when compared to rectangular waveguides.

[发布机构] Stellenbosch University