A GSM900/1800 Dual-Band MMIC Power Amplifier Using-Outside-Base/Center-Via-Hole Layout Multi-finger HBT

A GSM900/1800 Dual-Band AlGaAs/GaAs HBT(Hetero-junction Bipolar Transistor) MMIC power amplifier has been developed. It includes power amplifiers for GSM900 and DCS1800, constant voltage bias circuits and d.c. switch. A novel multi-finger HBT layout which can realize uniform output load impedance and thermal distribution of each HBT finger are applied to the final-stage HBT in order to achieve high efficiency. The developed MMIC amplifier has provided output power of 34.5dBm and power-added efficiency of 53.4% for GSM900, and output power of 32.0dBm and power-added efficiency of 41.8% for DCS1800.