Accurate closed-form formulas for the electromagnetic parameters of micromachined shielded membrane microstrip line

This article presents analytical expressions for the electromagnetic parameters (characteristic impedance (Z_c), inductance (L] and capacitance (C)) of micromachined shielded membrane microstrip line (SMM). The analytical expressions can be deduced from rigorous analyses using method of moments (MoM) analysis and curve-fitting techniques. An analysis can be readily implemented in modern CAE software tools for the design of microwave and wireless components. This study presents accurate and suitable general expressions for all micromachined SMM lines with a wide range of (w/h) ratio varying between 1 and 10. A micromachined branch line coupler operating at 80 GHz will be designed to demonstrate the usefulness of these design equations.