Study on Linearization Performance of Highly Efficient Low-Voltage Biased Driver Including Dual-Stage GaN MMIC

Linear amplification is an essential need for the transmitters of mobile communication systems using complex modulation schemes due to the required high fidelity phase and amplitude response. In this study, a new dual-stage high gain and efficiency driver amplifier and its linearization performance are presented. The GaN MMIC is implemented without an interstage matching network, and in particular, its first stage is biased at a lower voltage than a usual GaN HEMT biasing achieving higher line-up efficiency. The proposed concept does not cause an indeterministic phase response and mitigation on linearity regarding the AM-AM and AM-PM analysis. Therefore it is linearizable with the conventional DPD methods. The final circuit has 28.5 dB linear gain and 76% PAE at p5dB while the output power is around 35 dBm at 2.14 GHz. 39.2% efficiency and -55 dBc ACPR is measured at 29.5 dBm output power with a 7.5 dB PAR LTE5 signal at 4.5 dB back-off.