Non-orthogonality relations between complex-hybrid-modes: an application for the leaky-wave analysis of a laterally-shielded top-open suspended microstrip line

In this contribution, the orthogonality relations between complex modes are investigated to demonstrate the coupling effect which exists between TE/sup z/ and TM/sup z/ hybrid modes when power storage, loss or leakage is presented in the longitudinal direction of a transmission line. As an example, the Parallel Plate Waveguide (PPW) modes are used to study a laterally-shielded top-open microstrip line (LShMSW). The study of leaky-waves is a very interesting application of the novel orthogonality relations derived in this paper. This study is carried out using the correct and incorrect orthogonality formulations, and a comparison of results is made to check the validity of the proposed technique.