一种CMOS超宽带LNA的优化设计方法

An Optimization Design Methodology for CMOS UWB LNA

为实现性能更优的超宽带(UWB)射频前端低噪声放大器(LNA),本文提出了一种通用的基于CMOS工艺的超宽带LNA优化设计方法.基于源端电感负反馈的LNA电路模型,本文提出利用最优化的数学方法分别确定晶体管尺寸、输入匹配网络和负载网络各元件参数的方法,实现了较好的输入阻抗匹配,达到了较高的增益、较好的增益平坦度以及优秀的噪声系数,并具有较低的功耗;本设计方法所用无源元件不但适宜CMOS集成,而且对工艺偏差具有一定的忍耐力.仿真结果说明用上述方法设计的超宽带LNA在工作频带内能够达到预期的各项性能要求.

An optimization methodology is proposed for designing ultra-wideband （UWB） low noise amplifier （LNA） in CMOS technology to achieve better performance of LNA in UWB RF front-end. Based on the circuit model of inductively source degenerated LNA, we present a design method using mathematics optimization technology to get optimum transistor size and component value in input matching net and load net,leading to fine input matching,adequate and fiat gain ,excellent noise performance as well as low power consumption. Meanwhile, the passive components in the proposed circuit can be implemented easily in CMOS technology with tolerance of process variation. Simulation results show that UWB LNA using this design methodology can achieve expectable performance.