PHASED ARRAY FEED CALIBRATION, BEAMFORMING, AND IMAGING

Abstract

Phased array feeds (PAFs) for reflector antennas offer the potential for\nincreased reflector field of view and faster survey speeds. To address some of\nthe development challenges that remain for scientifically useful PAFs,\nincluding calibration and beamforming algorithms, sensitivity optimization, and\ndemonstration of wide field of view imaging, we report experimental results\nfrom a 19 element room temperature L-band PAF mounted on the Green Bank\n20-Meter Telescope. Formed beams achieved an aperture efficiency of 69% and\nsystem noise temperature of 66 K. Radio camera images of several sky regions\nare presented. We investigate the noise performance and sensitivity of the\nsystem as a function of elevation angle with statistically optimal beamforming\nand demonstrate cancelation of radio frequency interference sources with\nadaptive spatial filtering.\n