A Compact Wideband Circular Polarized Fabry-Perot Antenna Using Resonance Structure of Thin Dielectric Slabs

A wideband small-footprint circularly polarized Fabry-Perot resonator antenna is presented in this paper. The design employs a partial reflecting surface (PRS) consisting of thin homogeneous dielectric slabs separated by a small air gap. The PRS is analyzed using transmission line theory, which gives more insightful into the theoretical concept and provides a simple tool for design and optimization. An antenna prototype with overall size of 1.2λ
_fmin
× 1.2λ
_fmin
× 0.6λ
_fmin
has been fabricated and experimentally validated (λ
_fmin
being the free-space wavelength at the minimum operating frequency). The measured impedance matching and axial ratio bandwidths are approximately 55.7% and 47.7%, respectively. In addition, the antenna achieved 3-dB gain bandwidth of 50.9% with a peak gain of 15 dBi. Compared to previous designs targeting similar applications, the antenna proposed here possesses a simple geometry with light weight, ease of optimization and fabrication, as well as enhanced axial ratio bandwidth and 3-dB gain bandwidth.