Low-profile and end-fire antennas for airborne applications

Abstract

Recent years have witnessed a growing demand for low-profile and end-fire antennas, which can be flush-mounted for aircraft, missile, and unmanned aerial vehicle (UAV) applications. However, there are a lot of limitations associated with traditional end-fire antennas. For example, the performance of log-periodic, Yagi-Uda and Vivaldi antennas is very sensitive to the conducting ground-plane on which these antennas are mounted. H-plane horn antennas can hardly achieve wide bandwidth and maintain low profile simultaneously. In addition, although helical antennas are excellent candidates to achieve end-fire radiation of circular polarization, they are non-planar structures, which are unsuitable to be mounted on moving platforms in consideration of aerodynamic characteristics. In this thesis, we aim to solve these limitations and propose novel solutions to realize low-profile end-fire antennas with various characteristics such as wide bandwidth, high gain, circular polarization, etc., which are potentially very useful to be conformal and flush-mounted for airborne applications.