1 Department of Information Technology, Technical University of Denmark2 Department of Electrical Engineering, Technical University of Denmark
In the accessible literature is applied simplified calculation methods for coupled microstrips, as give a fair decision of the characteristic impedances within 10-20% accuracy. In this report it is succeeded to appear calculation methods that give the desired exactly calculations of differential mode impedance (identical to 2x odd mode impedance) and commom mode impedance (identical to 1/2x even mode impedance). The conformal mapping with Schwarz-Christoffel formula give no possibility for the inverse functions for a synthesis optimization. For that reason there is calculated figures, who can be used for stipulation of strip dimensions within 4% precision, referred to produced coupled microstrips and measured impedances. The report is initiated with exactly calculation of impedances for coplanar strips and microstrips, because these calculations apply to the calculations of coupled microstrips.