Wideband Fabry-Perot Resonator Antenna With Electrically Thin Dielectric Superstrates

This paper presents a design method of wideband Fabry-Perot resonator antennas (FPRAs) with two layers of electrically thin dielectric superstrates. The bandwidth enhancement mainly benefits from the superstrate structure with reflection phase increasing with frequency, which is used as a partially reflective surface. The proposed method is validated by a design example in X-band. Experimental results of the FPRA prototype demonstrate that the 3-dB gain bandwidth ranges from 8.5 to 11.2 GHz (relatively 28%) with a peak gain of 14 dBi and coincides with the impedance band for S11 ≤ -10 dB. Compared with the existing methods of gain bandwidth enhancement, the one presented in this paper does not need dielectric substrates with a large or fixed electrical thickness, improving cost performance and design flexibility.