A NEW NUMERICAL TECHNIQUE FOR CALCULATING CURRENT DISTRIBUTIONS ON CURVED WIRE ANTENNAS - PARAMETRIC B-SPLINE FINITE-ELEMENT METHOD

A new numerical technique is presented for calculating the current dis tributions on wire antennas with a high degree of curvature. The geome try of the wire antenna is expressed by a parametric equation and the current is directly expanded into a series of quadratic B-spline basis functions of the parameter, so that the truncation error in modeling the curved wire structure is avoided. This algorithm is used to analyz e a circular loop antenna, a conical equiangular-spiral antenna, and a four-arm Archimedian spiral antenna to demonstrate its validity and p ractical value.