Fast, accurate and simple approximate analytic formulas for calculating the parameters of supported coplanar waveguides for (M)MIC´s

Fast, accurate, and simple approximate analytic formulas are presented for calculating the quasi-static-TEM parameters of supported coplanar waveguide (SCPW) structures. These include the open, covered as well as dielectric over-layed SCPWs. These formulas have been designed for use in (M)MICs CAD programs and are only valid whenever the supporting material is of lower permittivity. Comprehensive comparisons have been made by using a rigorous spectral-domain hybrid mode analysis. Accuracy is found to be better than 1% for most of the operating range of physical dimensions and available dielectric materials (∈_r =1 to 20). Numerical results are also presented in order to investigate the properties of different SCPW structures