Publication: IEICE TRANSACTIONS on Electronics Publication Date: 1999/11/25 Vol. E82-CNo. 11pp. 1886-1894 Type of Manuscript: INVITED PAPER (Special Issue on High-Frequency/High-Speed Devices for Information and Communication Systems in the 21st Century) Category: RF Power Devices Keyword: HBT, InGaP/GaAs HBTs, AlGaAs/GaAs HBTs, MOCVD, reliability, microwave devices,