Multiple-mode resonance bands in periodically nonuniform conductor-backed coplanar waveguides

Abstract

The full-wave spectral-domain technique is developed to investigate the characteristics of periodically nonuniform MIC transmission lines. The Floquet's theorem is employed to express all the field quantities in terms of the spatial harmonics, so that the boundary-value problem of a periodically nonuniform transmission line can be treated similarly to that of the uniform one. The Galerkin's method in the Fourier-spectral domain with a set of appropriate basis functions is used to obtain the numerical results for the characteristics of the sinusoidal-shaped coplanar waveguides with/without backside ground. The multiple resonance bands produced by the dominant mode as well as the higher-order modes in these periodic structures are exploited theoretically and experimentally.