兼顾群延时与宽带匹配的SiGe HBT LNA设计

Design of SiGe HBT LNA Considering Group Delay and Wideband Matching

选用SiGe HBT作为电路的有源器件,利用基极串联电感LB与反馈支路、晶体管Miller效应所产生的寄生电容形成的T型匹配网络取得了输入阻抗的良好匹配,并就基极串联电感值对系统群延时的影响进行了讨论,优化LB以满足兼容群延时与宽带匹配的要求。该放大器在3.1-10.6 GHz的带宽内增益达到12.7 dB,增益变化小于等于1.8 dB,噪声小于3.85 dB,群延时小于24 ps,静态功耗仅为6.3 mW。

A resistive-feedback UWB LNA （uhra-wideband low noise amplifier） was presented. SiGe HBT was adopted as the active device of this LNA. A novel methodology was proposed to match the input impedance of this LNA with advantage of T-type matching network constituted of the serial inductance at the base, feedback loop and Miller capacitors. Meanwhile, the effect of the serial inductance on the group delay of this LNA was discussed for optimizing LB. The simulation results indicate the gain of LNA reaches as high as 12.7 dB with the variation of 1.8 dB, NF is less than 3.85 dB, group delay is less than 24 ps from 3.1 to 10.6 GHz and the power consuming is only 6.3 mW.