Triangular and rectangular elements in the spectral-domain analysis of arbitrarily shaped planar circuits

An existing approach for the spectral-domain analysis of planar circuits in layered media based on piecewise-sinusoidal current expansion functions over rectangular elements which are located parallel or perpendicular to each other is expanded to a wider class of geometric shapes. In a first step the rectangular cells are allowed to be arbitrarily directed in the plane of the circuit. In a second step triangular elements are used to combine arbitrary rectangular cells. Two kinds of current expansion functions with different computational effort are applied to the triangular and its two adjacent rectangular elements. Numerical results are presented