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 <inline-formula> <tex-math notation="LaTeX">$1.2\lambda _{f_{\text {min}}} \times 1.2\lambda _{f_{\text {min}}} \times 0.6\lambda _{f_{\text {min}}}$ </tex-math></inline-formula> has been fabricated and experimentally validated (<inline-formula> <tex-math notation="LaTeX">$\lambda _{f_{\text {min}}}$ </tex-math></inline-formula> 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.