A Compact Fabry-Perot Cavity Antenna with Circular Polarization

In this paper, a compact, circularly polarized Fabry- Perot Cavity (FPC) antenna is presented. The proposed solution consists of an opportunely designed microstrip resonator inserted within a closed cavity, measuring only
$3lambdatimes 3lambda$
at the working frequency of 412 MHz. The microstrip resonator is a dual circularly polarized slot-patch antenna. On the cavity top layer, a Partially Reflective Surface (PRS), based on an inductive Frequency Selective Surface (FSS) structure, is positioned. To verify the conceived design, accurate numerical simulations have been carried out. The obtained results show a gain value of about 19 dBi and an Axial Ratio (AR) less than 3 dB inside the 17° Half Power Beamwidth (HPBW). Moreover, the Side Lobe Level (SLL) remains under -13 dB. The compactness and the excellent radiative properties of the proposed cavity antenna are promising for challenging environments, such as space surveillance applications.