3～5GHz超宽带电流复用功率放大器的设计

Design of Power Amplifier with Current-Reuse for 3-5 GHz UWB

设计了一种工作在3～5GHz频段、具有极好的增益与平坦性的超宽带CMOS功率放大器(PA)。采用共源共栅级联共源结构的两级放大电路来克服功率增益的不足,采用电流复用技术提高工作频段内高频处的增益,级间电感和电阻并联负反馈结构可改善增益的平坦性。采用TSMC 0.18μm RF CMOS工艺库进行设计和仿真。仿真结果表明,输入回波损耗(S11)小于-8dB,输出回波损耗(S22)小于-4dB,平均功率增益为22dB,增益平坦度约为0.8dB。4GHz时输出1-dB压缩点为7dBm,功率附加效率(PAE)达到12.5%,电路总体功耗为33mW。

A CMOS power amplifier（PA） with good gain flatness was designed for 3-5 GHz UWB applications.In this work,cascode topology with an additional common source stage was adopted to increase the power gain,current reuse technique was used to enhance gain at upper end of the desired band,and an inter-stage inductor and a resistive feedback were used at the second stage to improve gain flatness.The PA circuit was designed and simulated based on TSMC＇s 0.18 μm RF CMOS process library.Simulation results showed that the power amplifier had an input return loss S11 less than-8 dB,an output return loss S22 less than-4 dB,an average power gain of 22 dB with a flatness of about 0.8 dB,an output 1-dB compression point of 7 dBm and a power added efficiency（PAE） of 12.5% at 4 GHz.The total power consumption of the circuit was about 33 mW.