Numerical short-open calibration (SOC) technique for de-embedding of periodic planar transmission line structures: Effective propagation constant and characteristic impedance

This paper presents the fundamental concept and formulation of short-open calibration (SOC) technique in 2.5D method of moments (MoM), and its application in commercial software. By de-embedding the port discontinuities and feeding network, the guided-wave characteristics of periodic planar transmission line structures, such as microstrip line, coplanar-waveguide electromagnetic band-gap, and metamaterial structures, can be extensively studied and analyzed. Especially, extraction of even- and odd-mode propagation constant and characteristic impedance of coupled microstrip line are discussed for synthesis and design of a few advanced bandpass filters.