Analysis of terminated lossless planar multilayer periodic EBG structures of DNG media using an equivalent BCITL model

Lossless planar multilayer periodic electromagnetic bandgap (EBG) structures of double-negative (DNG) media, terminated in a surface impedance with an arbitrary number of DNG layers in a unit cell, can be traditionally simplified by modelling these structures using equivalent periodic multi-section transmission lines (TL) terminated in a corresponding load impedance. In this paper, these periodic multi-section TLs can be effectively analyzed using an equivalent model based on bi-characteristic-impedance TLs (BCITLs), where their characteristic impedances with nonnegative characteristic resistances (NNCRs) and negative characteristic resistances (NCRs) are considered. It is found that the equivalent BCITL model yields accurate results by simplifying the analysis of these structures with more physical insight.