Analysis of coplanar lines utilizing the finite difference time‐domain technique

The full‐wave analysis methods in the time domain including the finite‐difference time‐domain method are promising as general‐purpose analysis techniques for three‐dimensional structures. They have been applied extensively to microstrip line circuits; and, in this paper, they are extended to coplanar line circuits and the finite‐difference time‐domain method is applied to the analysis of coplanar lines considered important as the configuration element for uniplanar monolithic microwave integrated circuits (MMIC). The analysis results are presented for the transmission line parameters of the coplanar waveguides and coplanar strips, models for open ends and short‐circuited ends, characteristics of the T‐junction and the effect of the air bridges. Using these analyses, the possibility of applications is proven. In addition, the points to be noted and future subjects are studied so that the method can be extended as a tool for the CAD of the MMICs.