SiGe HBTs for millimeter-wave applications with simultaneously optimized f/sub T/ and f/sub max/ of 300 GHz

Millimeter-wave applications are gaining growing interest in recent times. To meet the challenges for such applications, SiGe HBTs, with simultaneously optimized f/sub T/ and f/sub max/ of >300 GHz, are developed. To the author's knowledge, this is the first report of f/sub T/ and f/sub max/ both exceeding 300 GHz for any Si-based transistor. BV/sub CEO/ and BV/sub CBO/ are 1.6 V and 5.5 V, respectively, with peak current gain of 660. Noise measurement shows F/sub min/ of 0.45 dB and 1.4 dB at 10 GHz and 25 GHz with associate gain of 14 dB and 8 dB, respectively. The results indicate SiGe HBTs are highly suitable for the rapidly expanding millimeter-wave applications.