Modelling of the multiple-arm conical spiral antennas for various applications

The investigation results of the radiation characteristics of multiple-arm conical spiral antennas are presented. An exponential spiral winding law for conical antennas providing a given radiation mode is proposed on the basis of the local equivalence principle. Computation of the current on the curved wires is obtained by an integral equation method. Comparison of the conical spiral antenna radiation characteristics, including half-power beamwidth, beam orientation and axial ratio, with those of well-known spiral winding laws (equiangular, Archimedian) is carried out.