Theoretical Verification of Single-Reflector Compact Antenna Test Range With High Aperture Usage

Abstract

In the reflector-based compact antenna test range (CATR), the aperture usage is one of our most concerned problems. Higher aperture usage means that in a CATR with the same aperture reflector, a larger quiet zone (QZ) can be generated to measure a larger aperture antenna. In this work, we theoretically derive a method to design a single-reflector CATR with high aperture usage. Specifically, the radiation function of the ideal feed for the offset-fed CATR is deduced. An offset-fed parabolic reflector CATR with this ideal feed can generate a QZ with 100% aperture usage analyzed by geometrical optics (GO). An offset-fed CATR with a 3 m side-length rectangular aperture parabolic reflector is designed and simulated by physical optics (PO) and physical theory of diffraction (PTD) in GRASP10. With the proposed feed, the aperture efficiency can reach about 74% at 100 GHz and over 86% from 200 to 500 GHz. The simulation results of the QZ field distribution in the system with an ideal feed and a manufactured coaxial cavity horn feed are presented and analyzed. Besides, we also summarize amplitude ripple, phase ripple, and cross-polarization isolation in the QZ to illustrate the performance of the single-reflector CATR.