HEMT GaAs/GaN power amplifiers architecture with discrete dynamic voltage bias control in envelope tracking RF transmitter for W-CDMA signals

A new approach to the average efficiency improvement based on a combined 2-PAs architecture is presented. It uses discrete power control and dynamic supply voltage, which allows enhanced efficiency at low power level. It enables envelope tracking RF transmitter with higher average efficiency than classical approach. At 2.14 GHz CW we got an average efficiency of 42.5%, 6.1% better than the classical approach with equal peak P out = 35 dBm. The peak increment of PAE is 13.3% at 16.4 dB of power back-off.