183 GHz InP MMIC Based Radiometer

This paper describes the design and development of a state-of-the-art dual-channel 183 GHz InP based Monolithic Microwave Integrated Circuit (MMIC) radiometer. This is the world's first reported monolithic radiometer that operates at 183 GHz enabling high precision micro-miniature sensing of atmospheric chemistry components in this band. The radiometer features the following key components: a plug-in front end low noise amplifier module utilizing a broadband InP MMIC that sets the system noise figure, a low loss waveguide diplexer module, waveguide-to-microstrip transitions fabricated on Z-cut quartz, a mechanical design that can be easily modified to be hermetic, dual-channel output allowing double sideband detection, and a combination of HEMT and HBT InP and GaAs MMIC active components.