K-Band SiGe System-on-Chip Radiometric Receiver for Remote Sensing of the Atmosphere

System-on-chip (SoC) miniaturization of radiometric sensors could dramatically improve quantitatively the study of Earth's atmosphere in the microwave- and millimeter-wave frequency regions, enabling cost and weight reductions both for ground- and space-based observation instruments. This paper reports the analysis, design, implementation, and experimental characterization of the first K-band SoC Dicke radiometric receiver implemented in a commercial silicon-germanium technology under Space evaluations. The radiometric receiver exhibits a responsivity of about 760 kV/W and a noise equivalent power of about 232 fW/√Hz at the center frequency of 25.75 GHz. For a bandwidth of 2.5 GHz, the system achieves a resolution of 9 K for a relatively short integration time (1 s), 2.8 K for a medium integration time (10 s), and 0.9 K for a relatively long integration time (100 s).