Systematic mixed even- and odd-mode modeling of parallel tightly coupled transmission lines

Systematic mixed even- and odd-mode modeling for analyzing parallel tightly coupled transmission lines is presented. This coupled line model is composed of even- and odd-mode equivalent lines. And, the numerical approach is based on the modified central difference (MCD) method. The voltage and current waves propagating along the parallel tightly coupled transmission lines are monitored by the time domain analysis method. For verification of the proposed modeling, a five-section 3-dB parallel coupled line is demonstrated dynamically. In addition, the S-parameters obtained from the pulse responses are compared with those of the commercial simulator.