A Ka Band Coaxial Three-Reflector Zoom Antenna Based on the Principle of Optical Zoom

This paper presents a novel approach to design zoomable antenna at 30 GHz by using three reflectors and a TE
₁₁
mode circular waveguide feed. The main reflector and the feed is designed to remain in a fixed position, and a pair of moveable subreflectors are used as zoom components to control the Half-Power Beamwidth (HPBW). By rearranging the location of two subreflectors based on the principle of optical zoom, the HPBW can be broadened by about 2.8 times. The GRASP simulation results verify the feasibility of the design.