A Low Profile Three Axis Gimbal Assembly for Radome Measurements

摘要

This paper describes a unique three axis gimbal assembly used to test the performance of small radomes. The gimbal assembly supports thin, low profile antennas within the radome, and achieves the correct orientation of the antenna relative to the radome as the entire radome/antenna assembly is rotated for measurement of parameters such as transmission loss and boresight error. The gimbal provides roll, elevation, and azimuth compensation for the antenna within the radome using a small package, with the gimbal point located very close to the rear of the antenna. The axes are equipped with high resolution encoders to provide the very accurate antenna positioning required to demonstrate compliance with tight boresight error tolerances for the radome under test. The entire assembly is removable from the master positioning system for the purpose of switching the test range configuration from radome testing to standard antenna pattern testing.