Design of Aircraft Conformal Antennas for FM Radio Communications
Seungbeom Ahn (1), Howon Kang (2), Youggi Kim (2), Ikmo Park (3), Hosung Choo (1)
(1) School of Electronic and Electrical Engineering, Hongik University, Korea, (2) KHP System Department, Korea Aerospace Industries, LTD, Korea, (3) Department of Electrical and Computer Engineering, Ajou University, Korea
FM radios (30 MHz ~ 88 MHz) are essential for aircraft communication with a ground control stations. A simple monopole such as a whip antenna, center fed dipole antenna, and blade antenna are commonly installed on an aircraft for this FM radio communications. These antennas generally suffer from a lack of durability, high aerodynamic resistance, and heavy weight as they extrude from the aircraft body. To mitigate these problems, conformal antennas which conform to the aircraft surface, for example, by printing directly on the aircraft radome, are often used in recently developed aircrafts. However, the shortcomings of conformal antennas are a relatively low radiation gain and narrow bandwidth, and the antenna performance is highly dependant on the surface shape and location where the antenna is placed. In this paper, we propose an aircraft conformal antenna that has broadband characteristic with high radiation gain. To broaden the bandwidth and increase the radiation gain, we employed a mesh-grid structure as the main antenna body because the mesh-grid structure can generally achieve broad bandwidth characteristics by efficiently using the given antenna surface space. Then we insert an impedance transformer between the main antenna body and the coaxial feeder to step-up the low input resistance of the main antenna to match with a 50 Ω characteristic impedance. In addition to improve the matching, especially at low frequency bands, we mounted a lumped element matching circuit after the impedance transformer. We also examined the performance variation depending on the surface shape and location of the antenna using a full wave EM simulator (FEKO of EM software and systems). The designed antenna was built and installed on a military helicopter (KUH-Surion), and the antenna characteristics, such as a reflection coefficient, radiation pattern, and the bore-sight gain will be presented.
IEEE Antennas and Propagation Society International Symposium (APSURSI)
2010
July
Due to copyright restrictions articles are not available for download. They are however indexed on this site and search results will therefore correctly indicate if such terms are present in the articles.
