Effect of finite and different ground‐plane widths on quasistatic parameters of asymmetrical coplanar waveguides

Fast, accurate, and simple closed‐form expressions are presented for calculating the quasistatic TEM parameters of asymmetrical coplanar waveguides (ACPWs) with finite and different ground planes. The effect of the ground‐plane width and the asymmetry in the ground‐plane widths and in the spacings of ACPWs on the line parameters is investigated by using the formulas derived by conformal mapping techniques. Comparisons are also made between the present results and the results available in the literature for both the conventional coplanar waveguide (CPW) and the ACPW. The results in this article are in very good agreement with the results derived by the conformal mapping technique, by the variational formulation, and by the spectral‐domain method. It has been shown that the asymmetry of both ground planes and spacings leads to a significant change of the quasi‐TEM parameters with respect to cases of the finite and infinite ground planes. © 2000 John Wiley & Sons, Inc. Int J RF and Microwave CAE 10: 383–389, 2000.