Millimeter wave synthetic thinned aperture radiometer

Abstract

Imaging of temperature and humidity profiles of the atmosphere on a global scale with high temporal and spatial resolution requires a large aperture millimeter wave radiometer on geostationary orbit. We developed a prototype 50 GHz millimeter wave synthetic aperture radiometer and Low Noise Amplifier (LNA) MMICs and receiver technology for a 180 GHz synthetic aperture system. The 50 GHz system was tested in laboratory and in field with a 4-meter target disk by refocusing the array to near-field by digital phase corrections. The 180 GHz system development included novel 180 GHz MMIC LNAs that provide more than 100 GHz of bandwidth with more than 15 dB of gain and a noise figure of 3.7 dB.