Demonstration of 3D Printed Hexagonal High Gain Short Backfire Antenna with Hard EM Walls

摘要

A short backfire antenna with hard EM walls (hard SBFA) to provide high aperture efficiency is under development for dual-band (Ll and L2) GPS and other satellite applications. The antenna is excited by a slotted subreflector fed and supported by a two wire transmission line via a low loss air-filled coax matching network on the back. The antenna was optimized for maximum aperture efficiency at Ll and L2, which also resulted in greatly improved cross-polarization due to a more uniform amplitude taper over the aperture. The SBFA hexagonal aluminum cavity with 7.5 “apothem was built by 3D printing (additive manufacturing). The hard boundaries on the cavity walls were implemented with anisotropic impedance metasurfaces (AIM) on a foam liner. Aperture efficiency of 85% (Ll) and 96% (L2) were demonstrated. A 19” diameter circular A-SBFA was also designed, providing 92%/17.7 dBi (Ll) and 99%/15.8 dBi (L2) aperture efficiency/directivity.