Model of the coupled transmission line with a non-uniform dielectric

The mathematical model of the coupled transmission line (CTL) with non-uniform dielectric in its cross-section is presented in the article. Supposed mathematical model is created using the method of moments and the technique of partial images of the charges. The created model allowed us to determine the charge distribution on the signal conductors, capacitances per unit length, and characteristic impedances of the CPL, when even-, odd-, c- or -modes are excited in them. The accuracy of supposed model was verified using the software which was created by authors. In this article the authors investigated electrodynamical characteristics of CTLs when it sizes and the substrate permittivity were changed in a wide range. A comparison of the calculated characteristics of author’s model with the results from other articles showed that they coincided.