A novel Fabry-Perot resonator antenna using a double-layer partially reflective surface (PRS) to enhance the operating bandwidth is proposed. Two layers of double-sided printed substrate are employed as the PRSs. A higher-permittivity dielectric substrate is inserted between the two PRSs to produce a positive reflection phase gradient, which is essential to expand the bandwidth. A wideband aperture-coupled microstrip antenna is utilized as the feed antenna to further improve the working bandwidth. A prototype of the proposed antenna is fabricated and tested to validate the simulated results. The experimental results show that the designed antenna has a wide impedance bandwidth ( S 11 j j< À 10 dB) of 9.43-13.0 GHz (35.7%) with a 3-dB gain bandwidth ranging from 9.12 to 12.26 GHz (31.4%) and a peak gain of 15.4 dBi at 10 GHz.

A novel Fabry–Perot resonator antenna with a wide impedance- and gain-bandwidth is proposed in this paper. A wideband aperture-coupled microstrip antenna is used as the primary source, and a single-layer frequency selective surface with a positive reflection phase gradient is designed as a partially reflective surface. To validate the proposed approach, a prototype antenna operating in the X-band is designed, fabricated, and measured. Both simulation and measured results indicate that the proposed antenna exhibits wideband characteristics. The measured impedance bandwidth (| S11| < −10 dB) is 64.4%, ranging from 8.68 to 15.12 GHz. The experiments demonstrate that a 3 dB gain bandwidth of 31.9% from 8.61 to 11.80 GHz with a peak gain of 14.0 dBi at 10 GHz is achieved. In addition, the proposed antenna reveals good directional radiation patterns, low side-lobe level, and low cross-polarization over the whole working band.