基于0.15μm-GaN工艺的输入输出谐波调谐高效率功率放大器设计

Design of a High Efficiency Power Amplifier with Both Output and Input Harmonic Tuning in 0.15μm-GaN Technology

文章提出了一种面向毫米波应用的基于谐波调谐的单片集成(Monolithic Microwave Integrated Circuit,MMIC)功率放大器(Power Amplifier,PA).通过在晶体管输入和输出端对谐波终端进行控制,MMIC PA可以在高频实现高效率性能.本文提出的输出网络在匹配基频阻抗的同时,可以控制二次和三次谐波阻抗.此外,为了进一步提升功放效率,输入端的二次谐波阻抗也进行了调谐.在0.15μm碳化硅基氮化镓(Gallium Nitride on Silicon Carbide,GaNon-SiC)工艺上对所提出的功放架构和设计方法进行了仿真和测试验证.测试结果表明,PA在21.4~23 GHz的频带范围内,功率附加效率(Power Added Efficiency,PAE)大于39.2%,输出功率大于33 dBm.而PA工作频率为22.2 GHz时,测试的漏极效率最大达到63.7%,对应的PAE为50.2%,输出功率为34.1 dBm,仿真和测试结果基本吻合.整体电路尺寸只有1.87 mm^(2),因此单位面积的输出功率为1.31 W/mm^(2).和其他工作相比,本文提出的功放实现了较高的效率和功率密度.

This work presents a high-efficiency on-chip harmonic tuned power amplifier(PA)monolithic microwave integrated circuit(MMIC)for millimeter-wave applications.The efficiency of MMIC PA at high frequency can be im⁃proved by accurate harmonic tuning method and proper harmonic terminations at both the input and output port of the tran⁃sistor.The output second and third harmonic impedance are controlled simultaneously by the proposed matching network.Besides,the input second harmonic impedance is tuned to the optimum region to achieve high-efficiency performance.Based on 0.15μm GaN-on-SiC(Gallium Nitride on Silicon Carbide)process,the proposed PA topology and design method are verified by simulation and measurement.The fabricated PA has a measured bandwidth of 21.4 to 23 GHz.The PAE(Power Added Efficiency)is larger than 39.2%and the output power is larger than 33 dBm within the measured bandwidth.The maximum measured drain efficiency is 63.7%with an output power of 34.1 dBm at 22.2 GHz.The corresponding PAE is 50.2%.Close agreement between simulated and measured results is achieved for this PA.The total size of the PA is 1.87 mm2,resulting in a power density of 1.31 W/mm2.Meanwhile,the proposed PA has a high-efficiency and power densi⁃ty performance compared with other reported high-efficiency PAs.