Abstract:Some new types of coplanar transmission lines,rectangular microshield coplanar coupled lines [RMCCL],coplanar coupled rectangular microshield lines [CCRML],are proposed for MMIC applications,which are developed from the coplanar coupled lines [CCL],coplanar coupled striphnes [CCS]. The analytic formulas are presented for calculating the quasi-static TEM parameters of these coupled lines by means of exact conformal mappling techniques. Numerical results are also presented to illustrate the properties of these coplanar transmission lines.