一种采用65 nm CMOS工艺28 GHz高能效Doherty功率放大器

28 GHz high-efficiency Doherty power amplifier in 65 nm CMOS technology

为适应当前5 G通信芯片趋于高效率化的发展趋势,介绍了一种28 GHz线性度好、效率高的Doherty功率放大器的设计。该功率放大器采用了65 nm CMOS工艺中的双堆叠器件来实现,通过设置不同的栅极偏置电压VG1和VG2,控制Main PA作为的主功放和Vpeak PA作为辅功放的打开与关闭,输入匹配采用LC集总元件进行匹配,输出功率合成器改进了集总网络来匹配所需的输出负载,大大降低了损耗。与传输线设计相比,优化后的功率合成器具有较好的集成度,面积也有所减小。测试结果表明,该Doherty功率放大器的输出饱和功率(Psat)为25.2dBm,增益为14.3dB,1dB压缩点(P1 dB)为20.1dBm,峰值功率附加效率(PAE)为35.8%。与经典的B类功率放大器相比,该功率放大器的峰值PAE和线性度都有所提高。这对毫米波无线通信的应用具有重要意义。

In order to adapt to the current development trend that 5 G communication chips tend to be efficient.This article presents the design of a Doherty power amplifier with good linearity and high efficiency in 28 GHz band.The PA is realized by using two-stack devices in 65 nm CMOS technology.Control the opening and closing of Main PA as main power amplifier and Vpeak PA as auxiliary power amplifier by setting different gate bias voltages VG1 and VG2,Input matching uses LC lumped elements for matching,and the output power synthesizer improves the lumped networks to match the required output load,which greatly reduces the loss.Compared with the design of the transmission line,the optimized power combiner has a good integration,and the area is also reduced.The measured results show that the output saturation power(Psat)of the PA is 25.2 dBm,the gain is 14.3 dB,the 1 dB compression point(P1 dB)is 20.1 dBm,and the peak power added efficiency(PAE)is 35.8%.Compared with the classical class B power amplifier,the peak PAE and the linearity of the amplifier are improved.It is of great significance to the application of milli-meter microwave wireless communication.