Closed form expressions for the computer-aided design of suspended microstrip circuits for millimeter wave applications

In the paper, a combination of a dividing-the-capacitance approach and a curvefitting technique is used to derive closed form expressions for the characteristics of suspended microstrip line with zero strip thickness. These expressions are mainly used for the computeraided design of suspended microstrip circuits for millimetre-wave applications. Calculated results using the derived expressions are found to be in very good agreement with available numerical results. The range of validity of the derived expressions is also included.