A Simplified Model for Predicting the Installed Performance of Circularly Polarized Antennas

We propose a simplified equivalent model for predicting the installed performance of circularly polarized (CP) antennas. We use a set of infinitesimal sources to represent the irradiated fields of an antenna of interest; however, instead of using infinitesimal dipoles, our source is composed of a set of infinitesimal crossed dipoles, the most basic radiator that generates CP waves. This choice facilitates the optimization process and still maintains the analytical aspect of the model; the irradiated fields can be described analytically. We achieve a reduction in computational cost when comparing to direct modeling, without impairing the accuracy of the model during the antenna placement task, and a reduction of optimization time when comparing to classical dipole models. Also, the equivalent model building step has reduced a computational cost for CP antennas. In order to validate our model, we construct a scaled model of a circular cylinder with a top-mounted GPS antenna, and we measure its radiation pattern in an anechoic chamber. The experimental results are in remarkable agreement with those simulated using the proposed equivalent model.