A compact and reconfigurable low noise amplifier employing combinational active inductors and composite resistors feedback techniques  

作　　者：Zhang Zheng Zhang Yanhua Yang Ruizhe Shen Pei Ding Chunbao Liu Yaze Huang Xin Chen Jitian 张正;Zhang Yanhua;Yang Ruizhe;Shen Pei;Ding Chunbao;Liu Yaze;Huang Xin;Chen Jitian(Faculty of Information Technology,Beijing University of Technology,Beijing 100124,P.R.China)

机构地区：[1]Faculty of Information Technology,Beijing University of Technology,Beijing 100124,P.R.China

出　　处：《High Technology Letters》2021年第1期38-42,共5页高技术通讯（英文版）

基　　金：Supported by the National Natural Science Foundation of China(No.61774012,61574010)。

摘　　要：A compact and reconfigurable low noise amplifier(LNA)is proposed by combining an input transistor,composite transistors with Darlington configuration as the amplification and output transistor,T-type structure composite resistors instead of a simplex structure resistor,a shunt inductor feedback realized by a tunable active inductor(AI),a shunt inductor peaking technique realized by another tunable AI.The division and collaboration among different resistances in the T-type structure composite resistor realize simultaneously input impedance matching,output impedance matching and good noise performance;the shunt feedback and peaking technique using two tunable AIs not only extend frequency bandwidth and improve gain flatness,but also make the gain and frequency band can be tuned simultaneously by the external bias of tunable AIs;the Darlington configuration of composite transistors provides high gain;furthermore,the adoption of the small size AIs instead of large size passive spiral inductor,and the use of composite resistors make the LNA have a small size.The LNA is fabricated and verified by GaAs/InGaP hetero-junction bipolar transistor(HBT)process.The results show that at the frequency of 7 GHz,the gain S_(21)is maximum and up to 19 dB;the S_(21)can be tuned from 17 dB to 19 dB by tuning external bias of tunable AIs,that is,the tunable amount of S_(21)is 2 dB,and similarly at 8 GHz;the tunable range of 3 dB bandwidth is 1 GHz.In addition,the gain S_(21)flatness is better than 0.4 dB under frequency from 3.1 GHz to 10.6 GHz;the size of the LNA only has 760μm×1260μm(including PADs).Therefore,the proposed strategies in the paper provide a new solution to the design of small size and reconfigurable ultra-wideband(UWB)LNA and can be used further to adjust the variations of gain and bandwidth of radio frequency integrated circuits(RFICs)due to package,parasitic and the variation of fabrication process and temperature.

关 键 词：variable gain variable bandwidth low noise amplifier(LNA) resistance feedback tunable active inductor(AI) 

分 类 号：TN722.3[电子电信—电路与系统]