A Compact Integrated 675–693 GHz Polarimeter

The design of a single-sideband 675-693 GHz integrated polarimeter is presented here. The compact module, measuring 1.5” x 1.5” x 0.75” includes the OMT, RF LNAs, image-reject filters, mixers, IF LNAs, and LO active multiplier chain. Total power dissipation is expected to be approximately 6W. Receiver noise temperature is expected to be approximately 6000K SSB. The polarimeter has been machined and assembled with measurements to be presented at the conference.

I. Introduction

CURRENT millimeter-wave polarimetric radiometers are either unsuitably large for space applications, or are direct-detection instruments that lack the ability to reject ozone emission contamination by selectively filtering the signal in the IF stages. Suitably compact, light-weight and power efficient heterodyne instruments are required to enable polarimetric measurements for microphysical parameterization of ice clouds applicable to NASA's planned Aerosol, Cloud and Ecosystems (ACE) mission. An important heritage instrument for ice cloud measurements in an airborne platform is the Compact Scanning Submillimeter-wave Imaging Radiometer (CoSSIR), which has channels operating as high as 874 GHz and has flown since 2002. A future concept known as the Cloud and Precipitation Process Mission (CaPPM), is described in a recent white paper for the next decadal survey. Each of these missions, as well as a host of possible CubeSat projects and future planetary probes, will benefit from the more compact, power efficient and reliable integrated receiver systems that will be enabled by this effort.