Dual‐polarised wideband tightly coupled dipole array for airborne applications
Alexander D. Johnson, Jingni Zhong, S.M. Sekelsky, Elias A. Alwan, John L. Volakis
Abstract
An ultra‐wideband (UWB) array is presented for UHF‐S band (0.19–2.3 GHz) communications with an emphasis on dual‐linear polarisation and wide‐angle scanning. The array achieves 12:1 impedance bandwidth for a voltage standing wave ratio (VSWR) <3 at broadside with low‐angle scanning off broadside to 0°, 45°, 60° in the E ‐plane (VSWR < 3, 4, 3.1) and 0°, 45°, 60° (VSWR < 3, 3.8, 5.5) in the H ‐plane. A 7 × 11 prototype was fabricated and tested for verification. In addition, finite effects with respect to mounting UWB arrays in airborne platforms are discussed. Specifically, the effect of radomes, perfect electric conductor shielding walls and resistive walls on the gain of the designed tightly coupled dipole antenna was studied, showing that losses can approach 2 dB.