Verification of the shaped beam feed for high aperture usage efficiency single offset parabolic reflector compact antenna test range

In this letter, to verify that the shaped beam feed can enhance the aperture usage efficiency of a single-offset parabolic reflector compact antenna test range (CATR), a shaped beam horn is proposed. First, we obtain the radiation intensity function of the feed. Then, a coaxial cavity horn feed with a half-ring is designed to shape the illumination that reaches the main reflector. Measured results demonstrate that, with no edge treatment, the quiet zone size can be up to 75% of the main reflector diameter under 1.20 dB amplitude variations and 12 degrees phase variations at 102.40 GHz, and 70% aperture usage efficiency ranging from 102 to 103 GHz with phase variations less than 12 degrees and amplitude variations less than 1.40 dB. The design verifies that the shaped beam feed can enhance the aperture usage efficiency of a single-offset CATR.