Title: Miniature MMIC Low Mass/Power Radiometer Modules for the 180 GHz GeoSTAR Array    
Primary Author: Kangaslahti, Pekka
Organization: Jet Propulsion Laboratory
Co-Author(s): Alan Tanner (JPL), David Pukala (JPL), Todd Gaier (JPL), Bjorn Lambrigtsen (JPL), Boon Lim (JPL), Xiaobing Mei (NGC), Richard Lai (NGC)

We have developed and demonstrated miniature 180 GHz Monolithic Microwave Integrated Circuit (MMIC) radiometer modules that have low noise temperature, low mass and low power consumption. These modules will enable the Geostationary Synthetic Thinned Aperture Radiometer (GeoSTAR) of the Precipitation and All-weather Temperature and Humidity (PATH) Mission for atmospheric temperature and humidity profiling. The GeoSTAR instrument has an array of hundreds of receivers. The development work was performed in "Miniature MMIC Low Mass/Power Radiometer Modules for the 180 GHz GeoSTAR Array (MIMRAM)" technology development task within the ESTO Advanced Component Technology (ACT-05) program.

Technology that was developed included Indium Phosphide (InP) MMIC Low Noise Amplifiers (LNAs) and second harmonic MMIC mixers and I-Q mixers, surface mount Multi-Chip Module (MCM) packages at 180 GHz, and interferometric array at 180 GHz. A complete MMIC chip set for the 180 GHz receiver modules (LNAs and I-Q Second harmonic mixer) was developed. The MMIC LNAs had more than 50% lower noise temperature (NT=300K) than previous state-of-art and MMIC I-Q mixers demonstrated low LO power (3 dBm). Two lots of MMIC wafers were processed (cost sharing with IPP program) with very high DC transconductance of up to 2800 mS/mm for the 35 nm gate length devices. Based on these MMICs a 180 GHz Multichip Module was developed that had a factor of 100 lower mass/volume (16x18x4.5 mm3, 3g) than previous generation 180 GHz receivers.

The LNA and mixer MMICs developed in MIMRAM will be used immediately in the ESTO IIP-07 tasks "GeoSTAR technology development and risk reduction for PATH" and ‘Ka-band SAR Interferometry Studies for the SWOT Mission’. The developed LNAs were integrated in the airborne ‘High Altitude MMIC Sounding Radiometer (HAMSR)’that was developed under the IIP-98 and currently is funded to be installed onto the Global Hawk UAV for participation in NASA's Genesis and Rapid Intensification Processes (GRIP) hurricane field experiment in the summer of 2010.