用于SiGe HBT LNA的新型双有源偏置电路的设计  

Design of a Novel Dual Active Bias Circuit for SiGe HBT LNA

作　　者：张东晖[1] 张万荣 谢红云[1] 丁春宝[1] 赵昕[1] 刘波宇[1] 

机构地区：[1]北京工业大学电子信息与控制工程学院,北京100124

出　　处：《微电子学》2012年第2期224-228,共5页Microelectronics

基　　金：国家自然科学基金资助项目(60776051;61006059;61006044);北京市自然科学基金资助项目(4082007);北京市教委科技发展计划项目(KM200710005015;KM200910005001);北京市优秀跨世纪人才基金资助项目(67002013200301);模拟集成电路重点实验室基金资助项目(51439010804QT0101);北京市属市管高等学校人才强教计划资助项目

摘　　要：偏置工作点是影响低噪声放大器(LNA)线性度的因素之一。为了保证LNA能够更好地对信号进行线性放大,稳定的偏置工作点对于放大器来说显得尤为重要。提出了一种新型有源偏置技术,通过同时采用两个电流源为LNA提供直流偏置,以达到稳定放大器偏置工作点的目的。基于JAZZ 0.35μm SiGe工艺,采用该新型双有源偏置技术,设计了一款LNA。在1.8～2.2GHz频带时,放大器的增益为22.03±0.46dB,噪声系数小于3.7dB,2.0GHz时的输入3阶交调点(IIP3)为5dBm,相对于传统无源偏置的LNA提高了10dBm。仿真验证了该新型有源偏置技术对提高LNA线性度的有效性。Bias operating point has important influence on linearity of LNA.A fixed bias operating point is necessary for LNA to linearly amplify the signals.An improved dual active bias technology was presented,in which two parallel active bias circuits was used to supply DC bias for LNA to stabilize bias operating point of the amplifier.Based on JAZZ 0.35 μm SiGe process,an LNA was designed using the improved dual active bias technology.Simulation results showed that the LNA had a gain of 22.03 ± 0.46 dB,a noise figure（NF） below 3.7 dB,and an IIP3 of 5 dBm at 2.0 GHz over bandwidths ranging from 1.8 GHz to 2.2 GHz.Compared with a traditional passive biased LNA,IIP3 of the new circuit increased nearly 10 dBm,which demonstrated the effectiveness of the linearity enhancement of the improved dual active bias technology.

关 键 词：双有源偏置电路 低噪声放大器 线性度 噪声系数 输入3阶交调点 

分 类 号：TN722.3[电子电信—电路与系统]