DESIGN AND REALIZATION OF A MILLIMETER-WAVE SI SIGE HBT FREQUENCY-MULTIPLIER/

In this paper, the design of an active millimeterwave frequency double r using an Si/SiGe heterojunction bipolar transistor (HBT) as the acti ve device is studied. Simulations are made using a developed physics-b ased large-signal model for Si/SiGe HBT's, which includes thermal depe ndence. Despite the high-output operating frequency of the fabricated doubler being close to f(max) 67 GHz for the Si/SiGe HBT, the conversi on efficiency in a not completely optimized circuit is found to be bet ter than -12 dB, The 3-dB bandwidth for the doubler is approximately 7 .4%. These results are found to be comparable to a heterojunction fiel d-effect transistor (HFET) doubler operating equally close to its f(ma x). Simulated results of the doubler performance,vith varied terminati ng impedances for the HBT are presented as design aids.