微波无线能量传输功率放大器效率提升的 设计方法研究

针对用于微波无线能量传输系统中的微波功率放大器高效率需求，文章提出了一种提高功率放大器功率附加效率及输出功率的设计方法。通过功率放大器内部的功率流向统计，分析了反馈电容通道对高频功率放大器效率损失的影响，进而提出在栅极-漏极之间引入反馈谐振网络，提高晶体管内部漏极到栅极反馈支路的阻抗，减少产生的功率流向内部漏极到栅极支路，降低晶体管内部通道的功率损耗，从而保证在产生的总功率保持不变的前提下，增加了流向负载上功率，实现微波功率放大器输出功率的增加和功率附加效率的提高。验证电路仿真结果表明，功率放大器在5.78GHz~5.82GHz频率范围内功率附加效率均高于70%，漏极效率优于80.5%，输出功率高于10.5W。证明了该方法在提升功率放大器效率方面切实可行，研究成果对提高应用于微波能量传输系统的功率放大器效率提供有力支撑。

Research on the design method of improving the efficiency of microwave power amplifier

To meet the demand of the high efficiency power amplifier in microwave power transmission systems. A design method to improve the power-add efficiency and output power is proposed in this paper. Through the internal power flow statistics of the power amplifier, the influence of the feedback channel on the efficiency loss of the high-frequency power amplifier is analyzed, and then a feedback resonant network is introduced between the gate and the drain of the transistor to increase the impedance of the internal drain-to-gate feedback branch and to reduce the power loss of the internal of the transistor, resulting in the increasing of the power flow to the load while the total power generated remains the same, thus improving the power-add efficiency and output power of the power amplifier. The simulation results of the validation circuit show that the power-added efficiency is higher than 70%, and the drain efficiency is better than 80.5%, while the output power is higher than 10.5W in the frequency band of 5.78GHz~5.82GHz. It is proved that the proposed method is practical and feasible in improving the efficiency of power amplifiers, which will provide strong support for improving the efficiency of power amplifiers applied to the microwave power transmission systems.