LAUSR

Abstract The possibility of reducing sidelobe levels (SLLs) of the E-plane radiation patterns of high-gain rectangular horn antennas by modifying the field distribution on the aperture is studied in this paper. A simple and efficient method for controlling the field distribution on the aperture is proposed by sectionalizing the aperture and using conductive plates inside the antenna to obtain the required tapering for SLL reduction. The resulting radiation patterns indicate significant SLL reductions and remarkable gain improvements over a wide bandwidth. Looking from another aspect, the proposed method can be used for SLL reduction and length reduction of high-gain rectangular horn antennas in a wide frequency band. Finally, a prototype of the proposed E-plane sectionalized rectangular horn antenna with 9 sections is fabricated and tested, successfully. The SLL of the proposed antenna compared with traditional horn antennas is reduced from above -15 dB to below -20 dB and the gain is improved by up to 1.8 dB. The measured gain is above 24.5 dB at 10 GHz with 1 GHz bandwidth.