基于谐波控制的高效线性功率放大器设计

Design of efficient linear power amplifier based on harmonic control

为了满足当前第五代移动通信系统对高速率传输的要求,采用谐波控制的方法设计了一款高效线性功率放大器。结合三阶交调分量的产生机制,综合考虑基带阻抗、基波阻抗及二次谐波阻抗对输出功率、效率和线性度的影响,在保证效率的基础之上,改善功放线性度。并采用紧凑、便于集成的耦合线SIR(Step Impedance Resonator)带通滤波器作为输出匹配网络,实现对谐波的抑制。该功率放大器采用GaN HEMT器件CGH40010F,通过仿真与实物测试,验证了该方案的可行性,最终测试结果表明,功率放大器在中心频率3.4 GHz处,间隔5 MHz的双音信号下,输出功率为37 dBm时,对应的功率附加效率(PAE)为40%,三阶交调失真(IMD3)为-30 dBc,增益约为10.5 dB。

To satisfy the demand of high-speed transmission in the fifth-generation mobile communication system,a highly efficient linear power amplifier was designed using the harmonic control method.Combined with the generation mechanism of third-order intermodulation component,the effects of baseband,fundamental and second harmonic impedance on the output power,efficiency and linearity were considered to improve the linearity of the amplifier on the basis of ensuring efficiency.A compact and easily-integrated step impedance coupled line bandpass filter was used as the output matching network to complete the impedance matching function and achieve harmonic suppression.The power amplifier adopted GaN HEMT device CGH40010F.The feasibility of the solution was verified by both simulation and physical testing.The final test results show that at central frequency of 3.4 GHz,the output power is 37 dBm with corresponding power added efficiency(PAE)of 40%,IMD3 of-30 dBc,and gain of about 10.5 dB.