Hybrid EER transmitter using highly efficient saturated power amplifier for 802.16e mobile WiMAX application

We have demonstrated a highly efficient Hybrid Envelope Elimination and Restoration transmitter for IEEE 802.16e Mobile WiMAX application using a highly efficient saturated Power amplifier (PA). For the optimum H-EER operation, the PA has been designed to have a maximum PAE at the average V_ds region by using 10 W (P_3dB) GaN High Electron Mobility Transistor. The maximum Power-added efficiency (PAE) is a 74.07 % at the 14 V V_ds. The bias modulator designed using a Hybrid Switching Amplifier (HSA) has a 73.3 % of efficiency. In the interlock experiment, the transmitter has shown an excellent PAE performance of 45.9 % at an average output power of 33.07 dBm with drain efficiency (DE) of 48.86 %. By using digital predistortion technique, the Relative Constellation Error (RCE) has been satisfied the specification of -30 dB with -36.88 dB. When considering the saturated PA with constant drain bias, the average PAE of the proposed transmitter has been hugely improved, about 13.64 %. These results clearly show that the H-EER transmitter using the saturated PA can deliver the excellent PAE performance.