SiGe HBT-based active cold load: Design, characterization and stability measurements

Abstract

We report experimental results concerning the noise performance and the stability of an active cold load (ACL) realized with an SiGe heterojunction bipolar transistor at microwave frequency (1.4 GHz). The ACL exhibits return loss higher than 35 dB and a noise temperature less than 66 K. Stability measurements performed over 4 months with a dedicated noise injection radiometer indicates that this active load is very stable.