Computation of monopole antenna currents using cylindrical harmonics

An eigenfunction expansion method is considered for computing the currents on a simple monopole antenna radiating into the half-space over an infinite perfect electric conductor ground plane. To apply the method, the monopole is enclosed by adding a second, parallel ground plane. The original half-space region is thus replaced by an infinite sequence of images. This approximation allows the fields to be represented using cylindrical harmonics expansions in each of two subregions between the ground planes. Coefficients of these expansions are found by enforcing E/sub z/=0 along the monopole surface as well as the continuity of the fields at the interface between the two subregions. Exhaustive computational checks were performed using the Numerical Electromagnetics Code as a benchmark.<>