Role of complex modes in coplanar-waveguide-to-coplanar-waveguide discontinuity calculations

Abstract

The existence of complex modes in the lossless symmetrical shielded coplanar waveguide is demonstrated. Complex modes are found to occur only within a range of frequency and structural parameters. It is shown that exclusion of these modes in the analysis of coplanar waveguide discontinuities can cause the input reflection and transmission coefficients to converge to incorrect values, thus highlighting their importance in such problems.