Using linear sections instead of uniform ones to analyze the coupled nonuniform transmission lines

In this article, a new method is introduced to frequency domain analyze arbitrary coupled nonuniform transmission lines (CNTLs). The CNTLs are subdivided into several short linear sections instead of uniform sections. The chain parameter matrix of linear sections is obtained by expressing the voltages and currents by power series expansion. This method is applicable to all arbitrary CNTLs. The accuracy of the proposed method is verified using a comprehensive example. © 2008 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2009.