A Generalized Formulation of Electromagnetically Coupled Striplines

This paper presents a method of derivation of general expression for coupling which can he applied to coplanar as well as noncoplanar strips of equal and unequal widths arbitrarily located between ground planes and filled with layered substrate. Assuming TEM-mode propagation, the couping coefficient is determined in terms of self and mutual inductances. The method of derivation of these circuit parameters is also presented. The expressions for the fields required for analysis are obtained from Green's function formulation. Comparison of the numerical data with those obtained by other methods is presented.