An Efficient Method of Moments for Thick-Wire Antennas

Detailed formulation of a simple Galerkin method of moments (MoM) is presented. It is based on compact closed-form expressions of mutual impedance among filamentary sinusoidal monopoles. Using piecewise sinusoidal basis functions, the mutual impedance of thick-wire sections can be computed through an azimuthal integration of the mutual impedance between filamentary dipoles. Each element of impedance matrix is calculated through a rapidly convergent single integral only. This is unlike other MoM techniques, where double or triple integrals are needed to evaluate impedance matrix. In our formulation, it has been assumed that the wire current is uniform in azimuth, and changes along the axial direction only. No approximation on the segment length or radius of the thick-wire is made, and hence our formulation remains efficient for arbitrarily long/thick antennas.