The Advanced Short Backfire Antenna as an Element for Space-Based Phased Arrays

Metasurfaces have been used to greatly enhance the performance capabilities of well-known antennas. One example of this improvement in performance is the Advanced Short Backfire Antenna (A-SBFA), in which the metallic inner rim-wall of a short-backfire antenna is lined with an anisotropic impedance metasurface. A hexagonal A-SBFA has been shown to produce greater than 90% aperture efficiency at both the GPS L1 (1.575 GHz) and L2 (1.227 GHz) bands [1], while circular A-SBFAs are capable of greater than 100% dual-band aperture efficiency at a range of aperture sizes [2]. The A-SBFA technology is therefore an excellent candidate for service as an array element on next-generation Medium Earth Orbit (MEO) GPS satellite buses. In this report, we outline the development path that led to the current A-SBFA technology. We further describe studies which should be conducted to bring the A-SBFA to a higher level of technology readiness as a phased array element.