Technical memorandum simple solution of dispersion characteristics of shielded stripline

An analytical technique is presented to analyse the propagation constant of the TEM-like mode as well as higher-order modes in shielded microstrip transmission line, particularly at the most-needed high-frequency region. The method is quite general and is based on a variational expression for the propagation constant inside the structure. A simple expression is developed for the characteristic equation of the TEM-like modes, which is quite accurate particularly at high fre-quencies. Further, the method is equally valid for open structure by proper adjustment of the parameters.