Design of a Ka-Band LNA for SoC space-based millimeter-wave radiometers

This paper presents the design of a Ka-band two-stage LNA for System-on-Chip (SoC) space-based radiometers. The circuit features proper self-adaptive compensation to achieve robustness against temperature variations. The technology selected is a 250nm SiGe BiCMOS technology from IHP foundry. This selection is motivated by the space qualification of the above process, which is under development at IHP. An automatic design procedure for inductors has been developed on purpose. Preliminary simulations of the designed LNA show a conversion gain of 24 dB at 31.4 GHz with a noise figure of 3.5 dB. The obtained sensitivity is very promising for total power radiometric applications.