Compact Antenna Test Range Using Offset Gregorian Antenna for Over 100 GHz Antennas and Metamaterial Reflectors

In 6G wireless communication systems, the use of array antennas and metamaterial reflectors above 100 GHz is being considered to expand the communication area, and there is an urgent need to establish a high-precision evaluation system for array antennas and metamaterial reflectors, which are key components for 6G wireless systems. To meet these demands, we have developed a compact antenna test range (CATR) system using offset Gregorian antennas, which consists of a parabolic mirror and an ellipsoidal mirror, to evaluate the radiation patterns of antennas and RCS patterns of metamaterial reflectors in the 100 GHz to 300 GHz band. The double-mirror configuration has the advantage of shortening the distance between the parabola and the antenna to be evaluated, since a long focal length can be achieved in a small space. In this presentation, we report on the performance of the developed offset Gregorian compact range system and the evaluation results of the antenna and reflector. So far, we have succeeded in generating a uniform plane wave at a distance of about 1 m from the parabolic surface in an area including a circle with a radius of 400 mm. The amplitude difference is less than 0.7 dB compared to the antenna radiation pattern measured by the planer near-field measurement system. The amplitude uniformity and phase variation of the generated plane wave are reported.

I. Introduction

In 6G wireless communication systems, the use of array antennas and metamaterial reflectors above 100 GHz is being considered to expand the communication area, and there is an urgent need to establish a high-precision evaluation system for array antennas and metamaterial reflectors, which are key components for 6G wireless systems [1]. To meet these demands, we have developed a compact antenna test range (CATR) system using offset Gregorian antennas, which consists of a parabolic mirror and an ellipsoidal mirror, to evaluate the radiation patterns of antennas and RCS patterns of metamaterial reflectors in the 100 GHz to 300 GHz band. The double-mirror configuration has the advantage of shortening the distance between the parabola and the antenna to be evaluated, since a long focal length can be achieved in a small space.