A high linearity downconverter for SAW-less LTE receivers  

作　　者：蒋培晨 管锐 汪吴峰 陈东坡 周健军 

机构地区：[1]School of Microelectronics,Shanghai Jiao Tong University

出　　处：《Journal of Semiconductors》2012年第10期66-71,共6页半导体学报（英文版）

基　　金：supported by the National High Technology Research and Development Program of China(No.2009AA011608);the National Major Science and Technology Projects Program of China(No.2009ZX03002-004-02)

摘　　要：This paper presents a high linearity downconverter implemented in a 0.18μm CMOS process for long term evolution（LTE） receivers without a surface acoustic wave（SAW） filter.The proposed downconverter is composed of a transconductance（Gm） stage,a passive mixer,a current buffer,a transimpedance（TIA） stage,and a DC-offset cancellation（DCOC） loop.The current buffer is utilized to provide very low load impedance for the passive mixer at high frequencies and reduce the output voltage swing induced by out-of-band blockers.This technique improves the input referred third-order intercept point（IIP3） and second-order intercept point（IIP2） of the down-converter by 4.5 dB and 11 dB,respectively.The measured results show that the proposed downconverter achieves a voltage conversion gain of 29.5 dB,double sideband noise figure of 12.7 dB,out-of-band IIP3 of 13 dBm and IIP2 of more than 62 dBm.This paper presents a high linearity downconverter implemented in a 0.18μm CMOS process for long term evolution（LTE） receivers without a surface acoustic wave（SAW） filter.The proposed downconverter is composed of a transconductance（Gm） stage,a passive mixer,a current buffer,a transimpedance（TIA） stage,and a DC-offset cancellation（DCOC） loop.The current buffer is utilized to provide very low load impedance for the passive mixer at high frequencies and reduce the output voltage swing induced by out-of-band blockers.This technique improves the input referred third-order intercept point（IIP3） and second-order intercept point（IIP2） of the down-converter by 4.5 dB and 11 dB,respectively.The measured results show that the proposed downconverter achieves a voltage conversion gain of 29.5 dB,double sideband noise figure of 12.7 dB,out-of-band IIP3 of 13 dBm and IIP2 of more than 62 dBm.

关 键 词：LINEARITY downconverter long term evolution（LTE） passive mixer radio-frequency（RF） receivers 

分 类 号：TN929.5[电子电信—通信与信息系统] TN851[电子电信—信息与通信工程]