The Design of the Ka-band Lens Antenna for Navigation Radar on Helicopter

Moon, Sang-Man; Kim, Hyounk-Young; Kim, In-Kyu; Lee, Sang-Jong; Kim, Tae-Sik; Lee, Hee-Chang

Journal of the Korea Institute of Military Science and Technology 2004;7(4):53-60.

Sang-Man Moon, Hyounk-Young Kim, In-Kyu Kim, Sang-Jong Lee, Tae-Sik Kim, Hee-Chang Lee

KARI

헬기 장착 항행 레이더용 Ka-대역 렌즈 안테나 설계

문상만, 김현경, 김인규, 이상종, 김태식, 이해창

한국항공우주연구원 비행선그룹

Abstract

In this paper, the radar antenna of navigation radar on helicopter was suggested to Ka-band lens antenna. It is type of the streamlined convex lens to reduce the air resistivity when helicopter was navigated. Although aperture area is smaller than the standard antenna just like horns, the gain is higher and beamwidth is smaller than standard horns. We made the lens by using maximum flare angle of the horn and dielectric constant of the lens. As a result, when aperture diameter was 280mm and focal length was 145mm, the return loss -21.25dB, the gain was 32.2dBi, E and H beamwidth was $1.8^{circ}$(E-plane), $1.4^{circ}$(H-plane), nearly $1.5^{circ}$, and side-lobe level was -18.4 dB(E-plane), -19.5dB(H-plane) lower were presented. So this suggested type can be used for the radar antenna of navigation radar on helicopter, and it will possible just a little some sidelobe suppression by using the choked horn as a feeder horn.