Mitigation of Feed Horn Overlapping Condition for Multi-beam Parabolic Reflector Antenna

Abstract

In designing a contoured beam for communication satellite services, a reflector antenna remains the most preferred option. Previously, a multi-beam technique employing many feed horns at optimal feed positions was proposed to obtain a precise contour beam for Malaysia. However, it has led to feed horn overlapping when the beams were arranged closely. Therefore, this issue of beam allocation and feed horn size shall be addressed. In this article, an analysis of the relationship between feed position and beam direction is analysed through the Beam Deviation Factor (BDF). As a result, a useful design chart was derived for no feed horn overlapping conditions, which determines beam separation and feed horn size at different values of F/D. A practical application showing the Peninsular Malaysia beam coverage was demonstrated to validate the derived correlation. As a result, five multi-beams have been successfully designed with no overlapping feed horns. Through simulation, an excellent contour beam for Peninsular Malaysia was justified, featuring low side lobes, narrow beam width and high gain.