Equations for Microstrip Circuit Design

A method for determining the accuracy of computed impedance and wavelength data for microstrip is proposed. It is shown that the standard equations of Wheeler and Schneider have rather large errors. Revised equations for microstrip impedance and wavelength are given both for analysis and synthesis with accuracy better than 1%. A simple, accurate equation for the microstrip open circuit is presented. Experimental data on microstrip T-junctions are compared with existing theories. A new accurate equation is given for the reference plane displacement in the stub arm. Corrections are proposed in the existing equations for the other parameters of the equivalent circuit.