Direct and inverse problems solutions for coaxial and waveguide probes

The solutions of direct and inverse problems for coaxial and rectangular waveguide probe structures (CPS and WPS) with multilayered media are presented. The direct problems are formulated as the analysis of CPS and WPS using the integral equation method or stationary formulation of problems. It allows one to obtain fast algorithms for the direct problems. The inverse problems are the determination of slab parameters (permittivities, permeabilities, and thicknesses). The least square method and artificial neural networks (ANN) have been used to solve the inverse problems.