Theoretical design and predictions of volute antenna performance

To provide generic design guidelines for volute antenna elements over a wide range of parameters, a theoretical formulation and algorithm for computing the antenna radiation field have been developed. From these computed field values, the antenna directivity, 3-dB beamwidth, axial ratio, and front/back ratio can be evaluated for the purpose of design tradeoff considerations. The technical approach used is to compute the radiation fields for the helical wires and the straight-end connecting wires, based on a sinusoidal current distribution model along each of the four filaments or wires of the volute. Using axial length as a running variable, a complete tradeoff for the case of the half-turn, half-wavelength volute to meet certain special requirements was considered as an example for design analysis.<>