Advanced GaAsBased HBT Designs for Wireless Communications Systems

This chapter addresses critical issues in GaAs-based HBT device design and offers effective and practical solutions to enhance the linearity and efficiency in microwave power amplification and the reliability in device operation. The individual device layer designs (primarily, the emitter and collector layer structures) are presented first. The optimization of the overall device design is discussed according to the scaling rules of HBTs and the wireless communications system requirements. Novel HBT device structures based on advanced designs, processes, and/or materials are discussed as well.