Numerical analysis of probe-excited multiple-arm printed wire antennas

A unified current integral equation is formulated for N-arm printed antennas with an arbitrary arm shape. The parametric moment method is employed for the current distribution. A succinct expression for the radiation fields is obtained with the help of the saddle point method. The validity of the formulation is verified by comparing the computed current distributions and radiation patterns for two-arm and four-arm Archimedian spiral antennas with published results. Also, the numerical results for a two-arm circular open-loop and a small four-arm Archimedian spiral are given to show potential applications of the present formulation