Evaluation of currents´ distribution and two-port parameters of an arbitrarily shaped notch in microstrip line through a simple and novel technique

Employing an amalgam of Modal Decoupling technique of Multi Transmission Lines (MDMTL) and improved version of Rigorously Coupled Multi Strips (RCMS) in conjunction with closed expressions of step and gap in microstrip line one is able to determine both longitudinal and transverse currents´ distribution of any transverse discontinuities such as rectangular notch, circular notch, slit, etc, across the strip separately and independently and also to estimate any two-port parameters readily and accurately within a wide range of microwave frequencies. In this paper, first the transmission line is divided into non-uniformly narrow strips for finding the current distribution of a rectangular notch qualitatively which is chosen as a matter of simplicity, and then it is again divided but this time in a uniform way to calculate the s-parameters. The results are in very good agreement with those obtained by full wave analysis.