A compact passive broadband hexagonal spiral antenna array for VHF remote sensing

This paper presents the results of research exploring compact antenna design techniques for a desired 10:1 bandwidth in the Very High Frequency (VHF) band for remote sensing applications. A relatively compact antenna array has been developed to efficiently receive arbitrary RF signals across the entire 30 to 300 MHz VHF spectrum. Specifically, the antenna fits within a 3 meter cube, is capable of receiving both horizontally and vertically polarized signals, and has a single main beam that consistently maintains a beamwidth close to 45deg. Additionally it has only one output, and it is entirely passive, i.e. no power is provided to the antenna.