ANALYTICAL ANALYSES OF V, ELLIPTIC, AND CIRCULAR-SHAPED MICROSHIELD TRANSMISSION-LINES

Several new types of monolithic coplanar transmission lines, v, ellipt ic, and circular-shaped microshield coplanar waveguide, have been prop osed. The characteristic impedance expressions for those transmission lines have been derived using the conformal mapping method (CMM) under the assumption of the pure-TEM propagation and zero dispersion. In th e analyses of the elliptic and the circular-shaped microshield coplana r lines, the methods using the graphical approximation and taking the geometric mean value of the upper and the lower bounds to the size of the line are put forward to calculate the characteristic impedance of this two kinds of microshield coplanar lines. The numerical results sh ow the effects of the different shaped microshield walls on characteri stic impedances.