A monolithic 3.7 W silicon power amplifier with 59% PAE at 0.9 GHz

Low-cost and highly-efficient RF power amplifiers with high output power are necessary for today´s mobile communications. However, monolithic integrated silicon bipolar RF power amplifiers have not yet been reported operating at high power-added efficiency (PAE) around 60%. To date, only GaAs MMICs, GaAs hybrid modules or Si power-MOS modules have been reported. The reasons for this are conduction losses, switching losses and charge-storage effects of the silicon bipolar power transistor. Further, at low supply voltages around 3 V, the on-chip interstage matching circuit is critical for high PAE and high output power. This work presents an integrated 2-stage RF power amplifier for the 0.8-1 GHz band based on spiral on-chip transformers. The application target for this power amplifier IC is a GSM mobile. The chip is fabricated in a standard 25 GHz-f/sub T/, 0.8/spl mu/m, 3-layer-interconnect silicon bipolar production technology.