(Sub-)mm-Wave Antenna Measurements Up to 668 GHz on the MetOp-SG Ice Cloud Imager in a Compensated Compact Range

The antenna and geometric performance of the Ice Cloud Imager (ICI) radiometer, developed by Airbus Defence and Space Spain for ESA and EUMETSAT’s MetOp-SG program, has been verified. The measurements up to 668 GHz were performed in June 2022 in the Compensated Compact Range CCR75/60xi at Airbus Defence and Space in Ottobrunn, Germany. The first-of-its-kind instrument required an innovative antenna test setup.A new mechanical accommodation principle for accurate quasi-full-sphere pattern acquisitions was implemented. With help of the novel Search and Tracking System, frequency instabilities caused by ICI’s unlocked local oscillators were removed from the test signal. A measurement dynamic range of 65 dB at 668 GHz and up to 87 dB at 176 GHz was achieved.This paper presents the implemented test setup, exemplary correlation results between measured and simulated antenna patterns at ICI’s 325 GHz and 664 GHz channel, as well as a summary of the measured antenna and geometric performance.