A ray-tracing method to analyzing modulated planar Fabry-Perot antennas

A new approach for fast modelling of Fabry-Perot antennas with modulated partially reflective surfaces (PRS) using ray-tracing is proposed. For validation of the method, a configuration is introduced which consists of a cavity with a modulated PRS, fed internally by a magnetic dipole. The PRS consists of 18×18 square patches of varying size placed in a regular grid with a lattice constant of approximately λ₀/3 at 20GHz. The radiation pattern of the configuration is determined both by the presented model and by a full-wave solver which is used as a reference. The Directivity predicted by the model and the reference is 16.2 dB and 16.8 dB respectively which proves a good agreement.