Dual-Band 2×2 Cavity-Backed Antenna with Enhanced Out-of-Band Suppression for Tx/Rx Communication of UAVs at Ku-Band

Abstract

This study introduces a dual-band linearly polarized 2×2 element cavity-backed antenna for unmanned aerial vehicles (UAVs). The proposed antenna can cover entire Rx (10.512.5 GHz) and Tx (13.7514.5 GHz) bands of Satcom and datalink operations at Ku-band. The radiating part of the antenna contains four (2×2) radiating slots which are excited by a coupling slot at the end of the feeding waveguide and a 2×2 cavity power divider. Additional baffles placed between radiating slots at the aperture are used to increase the bandwidth and gain values of in-band and slightly improve out-of-band suppression. The antenna is fed by a rectangular waveguide which includes two third-order E-plane band-stop filters being placed on the opposite sides of broad wall of the waveguide to significantly suppress out-of-band frequencies between Tx/Rx bands and below Rx band which gives dual-band characteristics. The proposed full metal antenna has Rx and Tx bandwidths of 10.3612.54 GHz (|S<inf>11</inf>|< -10 dB, FBW = 16%) and 13.6314.7 GHz (|S<inf>11</inf>|< -10 dB, FBW = 7%) respectively. It has peak gain of 14.3 dBi with a stable in-band gain of 14.15 ± 0.15 dBi. Out-of-band rejection level of above 20 dB is obtained at the undesired bands of 9.810 GHz and 12.813.2 GHz. © 2024 Elsevier B.V. All rights reserved.