Study of Variable Coupled Striplines on Semiconductor by Determination of Depletion Layer

A numerical Green´s function is used to obtain the depletion layer-profile in two dimensions in a semi-conductor. The depletion layer profile is initially estimated from one dimensional Schockley approximation. Once the depletion layer is given, the charge density on the conductors is calculated by use of Green´s function. Knowing the charges on the strip~, one calculates the new depletion layer profile. The originality of the method is in introducing for the potential created by charges in the semiconductor. some trial functions of second order in x and y. An iterative procedure is then started. Convergence is obtained after 8 and 3 iterations respectively for the first and second trial functions. Direct calculation for equipotential curves is used for verification. The accuracy is almost 10-2. Characteristics of propagation in the quasi TEM mode of two variable coupled microstrip lines have been obtained.