Analysis of a square helix applicable to the personal satellite communication handset

The initial results from a study of one candidate antenna for a personal satellite transceiver handset, a square thin-wire helix, are presented with the intent to study the possible effects the presence of the operator will have on the radiation characteristics of circularly polarized antennas. The method of moments (MOM) is used to perform a full-wave analysis of the square thin-wire helix mounted on a small conducting box, and its performance is shown to be similar to a standard (circular) helical antenna. In addition, the geometry of the square helical antenna readily allows it to be simulated with a cartesian grid finite-difference time-domain (FDTD) code that can also incorporate a model of a human head in the analysis. The effect the head model has on the computed far-field pattern and axial ratio is presented.