CubeSat scale receivers for measurement of ice in clouds

Global measurements of ice in clouds, both the amount and particle size distribution, are critically needed to reduce uncertainties in global climate models. The retrieval of this information is best achieved with a range of receiver channels across the submillimeter wave range. Advancement of low noise Indium Phosphide (InP) MMIC amplifier technology enabled us to develop miniature submillimeter-wave receivers for a CubeSat scale instrument that achieves 6 km spatial resolution. The heritage of InP MMICs includes continuous operation for four years in the PLANCK Low Frequency Instrument and providing world-record sensitivity with high reliability in several airborne instruments. We have developed a set of InP MMICs for receivers at 240, 310, 380 and 670 GHz with significantly lower noise than previously reported. The noise temperature is NT=450 K at 240 GHz, NT=550K at 310 GHz and NT=650 K at 380 GHz. The 670 GHz LNAs provide a NT of 2400 K. These channels are complemented by the previously-developed and airborne-proven 183 and 118 GHz MMIC receivers that were tested to TRL 6.