Wideband aperture-coupled antenna array based on Fabry–Perot resonator for C-band applications

摘要

A novel Fabry–Perot resonator (FPR) antenna array in a C-band, which produces broader gain bandwidth, flatter radiation efficiency and wider circular polarisation in comparison with conventional antenna arrays, is introduced. These improved characteristics are obtained using a superstrate constituting two complementary frequency selective surfaces placed above a 2 × 2 antenna array and fed by a 4 × 4 modified Butler matrix. The performance of the FPR antenna was verified by simulated and experimental outcomes. The experimental results indicated that the FPR antenna array possesses an impedance bandwidth between 3.7 and 8.55 GHz for S11 ≤ −10 dB, which covers the C-band fully (4–8 GHz). Moreover, the impedance bandwidth is approximately covered by the 3 dB gain bandwidth between 4.4 and 7.5 GHz with a peak value of 18.1 dBi. Finally, the FPR antenna array has a 3 dB axial-ratio bandwidth of 3.5 GHz between 4.35 and 7.85 GHz that includes major wireless standards.