Unified 3-D definition of CPW- and CSL-mode characteristic impedances of coplanar waveguide using MOM-SOC technique

Characteristic impedances of two dominant modes, even CPW- and odd CSL-mode, in the coplanar waveguide (CPW) are defined and characterized with resorting to the network equivalence of a finitely extended CPW line in a three-dimensional (3-D) method of moments (MoM) platform. By introducing the port model with a pair of even or odd symmetrical current sources, a determinant MoM scheme is at first formulated to establish the explicit relationship among the port currents and voltages. A short-open calibration (SOC) technique is then accommodated in this MoM to remove the parasitic port discontinuity effects. Our results are compared with those of the two-dimensional (2-D) definition and demonstrate for the first time the equivalent 3-D characteristic impedances of both CPW- and CSL-mode.