Spectral domain analysis of planar circuits with rectangular and triangular elements and its application to the calculation of triangular patch antennas

We present an approach for the spectral domain analysis of planar circuits in layered media based on the combination of piecewise sinusoidal current expansion functions over rectangular elements and constant or linear varying expansion currents over triangular elements. All elements are allowed to be arbitrarily directed in the plane of the circuit. We applied the method to the calculation of triangular patch antennas and present numerical results for different subdomain expansions. The results are compared to measured data.