Computational Analysis and Validation of the Cylindrical TLM Approach on IMCP Antennas

Numerical computational methods on a Cartesian grid and analytical approaches face many problems and limitations when modeling antenna structures of circular/cylindrical geometry is concerned. This paper presents possibilities and computational demands of the cylindrical TLM approach with a wire modeling ability, implemented through in-house developed 3DTLMcyl_cw solver, when it is used as an accurate and efficient alternative for the design and analysis of inverted configurations of coaxially fed circular patch antennas. To emphasize the approach advantages, a thorough investigation of a polar mesh extension and resolution influence on simulated results has been carried out including an optimization of a coaxial feed position. The approach has been used to design IMCP and CB-IMCP antennas in order to determine antennas parameters and to study an influence of a substrate permittivity, an air-gap height and a metallic cavity presence on antennas’ performances. Accuracy of the approach has been experimentally verified, while its advantages have been pointed out with regards to the corresponding Cartesian TLM mesh and the approximate cavity model.