Design and characterization of MMIC active cold loads

This paper reports the first broadband monolithic microwave integrated circuit (MMIC) active cold loads. The fabricated loads demonstrate state-of-the-art temperatures of 90 K over the 2-10 GHz range and 125 K over the 10-26 GHz range. The MMICs were fabricated on 100 micron GaAs substrates using 0.15 micron GaAs metamorphic HEMT technology. In addition, contemporary topologies for cold load design have been evaluated.