The Research And Design Of Power Amplifier With High Linearity Applied For Micro Base Station

With the rapid development of communication technology,various intelligent device terminals have greatly enriched people's lives.In order to meet the increasing demand for high-speed signal transmission and multi-terminal device connection,the research of the 5G mobile communication technology is carried out.In order to solve the problem of high-rate transmission,the high PRAR modulation signal will be widely used in 5G communication,but the high PRAR will bring nonlinear distortion of the signal,which puts higher requirements on the power amplifier.The base station is one of core devices of the wireless communication system,and the power amplifier is located at the front end of the base station transmitter.It is the most power-consuming and non-linear device in the base station and its performance directly affects the base station's transmission performance and communication quality.The linearization technologies used in power amplifier have also become the key to base station PA research.The paper first introduced the theory of semiconductor devices,compares the substrate materials commonly used in the current power amplifier market,and established a model of GaAs HBT devices,then introduced the indicators of power amplifier and traditional linear power amplifier.After analyzed the nonlinear distortion of the power amplifier,we introduced the current linearization techniques such as feedback,trade-off,and predistortion.Finally,a power amplifier applied for micro base station is designed using a GaAs HBT process.The chip is aimed at the sub-6GHz band,and the operating frequency is 2110 MHz to 2200 MHz.The power amplifier adopts a three-stage amplification structure.Based on the specifications of the 3GPP,the design focuses on the adaptive bias circuit and the output matching circuit,and uses the power back-off technology to improve the linear characteristics.For more precise,passive parts such as output matching and bonding wires are electromagnetic simulated in HFSS,then simulation results are brought into ADS for joint simulation.In the layout and laminate design,the parasitic effect is fully considered.The final test results show that the power amplifier has a saturated output power of 33.5dBm and a gain of 35 dB.When the input power is changed from-30 dBm to 5dBm,the gain flatness is 0.5dB.At the output power of 25 dBm,the power added efficiency is about 16%,and the ACLR is less than-47 dBc,meeting the design requirements.