Generalised Transverse Resonance Method for Nonuniform Lines in Microwave Integrated Circuits (MIC)

A new "Generalised Transverse Resonance Diffraction Method" is presented for obtaining an analytical description of dispersion characteristics and complex impedance of non-uniform Printed Transmission Lines as a function of position. A single "taper mode" is recovered that exactly satisfies regular, singular and, possibly, vertex boundary conditions along the whole guide, and such that no coupling is present between progressive and regressive waves and between different taper modes. Taper modes degenerate into the conventional ones as the guide returns to uniformity. Consequently, the results are particularly suited for application in equivalent-line approaches and an example of unilateral fin-line linear taper is reported.