The Design Of GaN Power Amplifier For 5G Mobile Communication

In order to adapt to the development of the 5th generation mobile communication system,the RF power amplifier which is the core part of the transmitter needs to meet new requirements in terms of operating frequency,power,efficiency,circuit size,and linearity.A GaN hybrid miwcrowave integrated circuit power amplifier with two-level asymmetric Doherty was designed by exploiting 0.45 ?m GaN HEMT technologies on SiC substrate,which has a higher collector efficiency under a larger power back-off state.The circuit was miniaturized by using passive lumped components to build the power divider,and quarter-wave impedance transformer could be fully integrated using ?-type structure.The Doherty power amplifier designed in this thesis could effectively solve the problems caused by the large peak to average power ratio.In order to improve the linearity of the Doherty power amplifier,digital pre-distortion technology was used to reduce the adjacent channel power ratio in this thesis.The test results show that the saturated output reaches 45.2d Bm and saturated drain efficiency reaches 53.2% in the frequency range from 3.4GHz to 3.6GHz.When the power is backed off by8 d B,the drain efficiency is 40% and the power gain is 24 d B.The ACPR which optimized by the DPD technology is-50.8d Bc when driven by 80 MHz long term evolution signal.The size of the circuit is 10mm×6mm.