S波段GaN MMIC Doherty功率放大器

Design of S-band GaN MMIC Doherty Power Amplifier

采用SiC衬底0.25μm Al GaN/GaN高电子迁移率晶体管工艺,研制了一款S波段GaN单片微波集成电路(MMIC)Doherty功率放大器,在回退的工作状态下仍可以保持较高的效率,可用于小型基站。为减小芯片尺寸,采用无源集总元件替代四分之一阻抗变换线;在输入端没有采用功分器加相位补偿线的结构,而是设计了一种集总结构的电桥来提高集成度。脉冲测试表明,在3~3.2 GHz频率范围内,饱和输出功率大于10 W,在回退6 dB处的功率附加效率(PAE)为38%,芯片尺寸为4.0 mm×2.4 mm。

An S-band GaN Microwave Monolithic Integrated Circuit Power Amplifier(MMIC PA)is designed and manufactured by exploiting 0.25μm AlGaN/GaN High Electron Mobility Transistor(HEMT)technologies on SiC substrate.The proposed power amplifier can be applied to the small-cell base.To reduce the size and loss,quarter-wave impedance transformer can be fully integrated using lumped passive elements,and the branch-line couplers are represented by lumped elements in the input matching network.The fabricated PA exhibits,at 3-3.2 GHz in pulse-wave conditions,an output power of 10 W,with a power-added efficiency of 38%at 6 dB of output power back-off.The chip size is 4.0 mm×2.4 mm.