A Broadband, Compact Low-Power microwave Radiometer Down Converter for Small Satellite Applications

The system includes a fundamental local oscillator (LO) source composed of a broad-band tunable frequency synthesizer as well as a crystal oscillator. The synthesizer employs a harmonic doubler to expand frequency coverage. The CubeRRT system uses a series of RF switches and band-pass filters, to select the desired harmonic while suppressing unwanted harmonics. The CubeRRT system uniquely combines several technologies to minimize the number of frequency banks and thus reduce mass, volume and power requirements. The CubeRRT system uses four frequency banks in order to provide continuous microwave receiver coverage from 6GHz to 40GHz. CubeRRT (CubeSat Radiometer Radio Frequency Interface Technology) is designed for remote earth sensing. The CubeRRT payload has three critical pieces of technology, a wideband antenna unit, a radiometer front-end (RFE) unit, and a radiometer digital back-end (RDB). In order to accommodate these components, Goddard innovated the CubeRRT (CubeSat Radiometer Radio Frequency radiometer) to be compact and operate at a low-power.