Improved hybrid SiGe HBT class-AB power amplifier efficiency using varactor-based tunable matching networks
This paper presents a 1.8GHz prototype class-AB power amplifier using a QUBIC4G (SiGe, f/sub t/ = 40GHz) handset device with adaptive in- and output matching networks. The realized amplifier provides: 13dB gain, 28 dBm output power, with an efficiency greater than 33-51% over a 10dB output power control range.