Equivalent circuit parameters of coplanar stripline discontinuities

The paper reports a study of equivalent capacitances and inductances of various coplanar stripline (CPS) discontinuities. To deal with equivalent capacitance, an integral equation for governing the distribution of excess charge near CPS discontinuity is derived and subsequently solved by the method of moments together with Galerkin´s approach. The equivalent inductance is determined from the equivalent capacitance of its complementary structure, i.e. a coplanar waveguide discontinuity in free space by means of the duality concept. Numerical results for the open end, the symmetric step, the short end, and other extensive discontinuities are presented. In addition, simulated results in a quasistatic model are compared with data obtained by the FDTD method