Mode Matching Analysis of Partially Filled Waveguide for Determining Electrical Property Parameters of Penetrable Materials

Determination of electrical property parameters like permittivity and permeability for penetrable materials is very important in many applications. There are several common techniques such as resonant cavity method, free space method, and waveguide method which can achieve the purpose. Partially filled waveguide method is another one that enjoys the feature of reduced fabrication precision requirement for the dielectric sample under test. In the original paper proposing the partially filled waveguide method, only TM modes are considered. Through mode matching analysis, we will show in this paper that both TM and TE modes shall be included in order to obtain a correct result.