No abstract

A 1710-1755MHz hybrid power amplifier module (PAM) consisting of a CMOS driver and a GaAs HBT output stage is described. By using multiple parallel CMOS driver stages the gain and bias current expansion needed to maintain the linearity into class C operation of the bipolar output stage is generated. This extends the linear output power range by 0.5 dBm and increases the power added efficiency (PAE) at ACLR1 of -40dBc from 39.0% at 28 dBm output power to 41.3% at 28.5 dBm output power for a WCDMA modulated signal. The PA achieves 43.5% PAE at 29 dBm Pout for an ACLR1 of -37 dBc with a gain of 26 dB and supply voltage of 3.4V.