Paper Title
Study on INGAP/GAAS Collector-up HBTS with the Graphene Base for Power-Amplifier Applications

Abstract
In this work, the characteristics of novel InGaP/GaAs collector-up heterojunction bipolar transistors with the graphene base and the nonuniform doped collector are demonstrated, and performances of the novel HBTs have been compared with the conventional InGaP/GaAs HBTs with various collector structures and thermal schemes. As compared to the conventional HBTs, the studied C-up HBTs exhibited better current-driving capability and higher RF efficiency. Note that the pnp device displayed greater thermal stability enhancement, which are distinct and reproducible, than the n-p-n device. The comparison results, based on pragmatic observations from the C-up HBTs without relatively large heatdissipation configurations, should be very useful for the reliable and the cost-effective design as small-scale power amplifiers in the wideband CDMA (W-CDMA) system. Keywords- Collector-Up, Graphene, Heterojunction Bipolar Transistors, Power Amplifiers, Thermal Stability.