Hybrid wave propagation in circularly shielded microslot lines

Hybrid wave propagation in circularly shielded, single or coupled microslot lines is studied by combining singular integral equation (SIE) with Green´s function techniques. Discretization of these SIE´s by recently developed algorithms leads to linear algebraic systems whose matrix elements assume exponentially converging, numerically very stable analytical expressions. Dispersion characteristics, modal currents, and cutoff frequencies are presented for several cases. The algorithm converges rapidly requiring a few expansion functions per wavelength