A Large Spherical Near-Field Arch Scanner for Characterizing Low-Frequency Phased Arrays
Author: Scott McBride, Jeffrey P. Marier, Charles J. Kryzak, Jeffrey Fordham, Kefeng Liu
An arch-based spherical near-field measurement system has been commissioned at Lockheed Martin’s facility in Syracuse, New York. This system is designed for highfidelity testing of large, low-frequency, phased-array radars. The near-field scanner system consists of a 9.5- meter-radius arch with an active probe-position-error correction, and a large azimuth axis capable of carrying large arrays. The shielded anechoic chamber designed to house the measurement system includes full treatment with curvilinear absorber to achieve low levels of stray signal at UHF band frequencies, FM-200 / VESDA fire protection, and a glycol based system for removing heat loads generated by the radars.
The overall measurement system details are presented, along with mechanical accuracies achieved for the scanner system. Details of the chamber and host facility are described. Finally, the paper concludes with measurements of a UHF-band Standard Gain Horn using the system. The challenges and benefits of such a system will be highlighted.