基于GaAs HBT工艺的高增益宽带Doherty功率放大器设计

Design of a High Gain and Broadband Doherty PA Based on GaAs HBT Process

在传统Doherty功率放大器的基础上,采用砷化镓(GaAs)异质结双极晶体管(HBT)工艺,设计了一款可应用于5G通信N79频段(4.4~5 GHz)的高回退效率MMIC Doherty功率放大器(DPA)。通过在Doherty电路中采用共射-共基结构,并在共射-共基结构中加入共基极接地电容,大幅提升了DPA的增益和输出功率。使用集总元件参与匹配,减小了芯片的面积。仿真结果表明,在目标频段内,增益大于28 dB,饱和输出功率约为38 dBm,饱和附加效率(PAE)为63%,7 dB回退处的效率达到43%。

Based on the traditional Doherty power amplifier,a MMIC Doherty power amplifier with high back-off efficiency for 5G communication in N79 band(4.4~5 GHz)was designed in a GaAs heterojunction bipolar transistor(HBT)process.By using cascode structure in Doherty circuit and adding common-base grounding capacitor in cascode structure,the gain and output power of DPA were greatly improved.Lumped elements were used to participate in the matching,which reduced the area of the chip.The simulation results show that in the target frequency band,the gain is greater than 28 dB,the saturation output power is about 38 dBm,the saturation added efficiency(PAE)is 63%,and the efficiency of 7 dB output power back-off is 43%.