In order to calculate the quasi-static TEM parameters of shielded coupled coplanar waveguides (SC CPWs) and shielded broadside-coupled coplanar waveguides (SBC CPWs), closed-form analytical formulas are obtained and presented using conformal-mapping techniques. The variation of electrical parameters with respect to different physical dimensions is observed for each type of transmission lines under investigation. The obtained results are also confirmed by comparison with the results in the literature. Further verification has been realized via Sonnet electromagnetic-circuit solver software. The proposed method in this study is thus well proved by these compared results. (c) 2006 Wiley Periodicals. Inc.