Packaging performance of GaAs/InGaAs/InGaP collector-up HBTs as power amplifiers

GaAs/InGaAs/InGaP collector-up heterojunction bipolar transistors (HBTs), with an effective thermal-dissipation packaging (TDP) configuration, have been developed. The TDP-implemented multi-finger collector-up HBT with a graded InGaAs base is demonstrated to achieve compelling high-speed and heat-removing performances. Extraordinarily, the TDP has a stronger influence on the p-n-p device than on the n-n-p device. The results show that the thermal resistance has been substantially decreased by 50%, and a power-added efficiency (PAE) more than 56% is obtained. Thermal performance for miniature power amplifiers in next-generation cellular phones can be greatly improved from our design.