W-band active loads and switching front-end MMICs for radiometer calibration

A millimeter-wave monolithic integrated circuit consisting of a W-band (75-100 GHz) single-pole-five-throw (SP5T) switch and multiple internal active and passive loads for radiometer calibration was designed and manufactured in a low noise 50 nm GaAs metamorphic high electron mobility transistor technology. This highly compact and integrated front-end device for radiometer systems is capable of ultra fast switching between two identical input ports (e. g. for polarimetric applications) and three internal calibration references. It allows an accurate multi-load calibration with noise temperatures between 220 and 1750 K at the output of the device. Compared to conventional calibration methods this marks a substantial advantage in terms of size, mass, power consumption, complexity, and repetition rate.