无线传感器网络的2.4GHz低功耗低中频射频接收前端的设计  

Design of a 2.4GHz low power low-IF RF frontend for wireless sensor metworks

作　　者：张萌[1,2,3] 李智群[1,2,3] 沈董军[1,2,3] 

机构地区：[1]东南大学射频与光电集成电路研究所,南京210096 [2]射频集成电路与系统教育部工程研究中心,南京210096 [3]江苏省传感网技术重点实验室,无锡214135

出　　处：《高技术通讯》2013年第4期413-420,共8页Chinese High Technology Letters

基　　金：863计划(2007AA0122A7);江苏省科技成果转化基金(BA2010073)资助项目

摘　　要：在0.18μm CMOS工艺下设计了一种用于无线传感器网络的具有低功耗、低中频特性的2.4GHz射频前端。该射频前端由一个共栅结构的可变增益低噪声放大器(VGLNA)和一个低功耗折叠正交吉尔伯特结构混频器构成,内部同时集成了一个给混频器提供IQ差分本振信号的二分频器以及一组缓冲器。其低噪声放大器具有高、低两个增益模式。为了弥补共栅低噪声放大器在增益和噪声等性能方面的不足,选取有一定增益的折叠吉尔伯特有源混频器结构。对共栅结构的低噪声放大器的设计过程、相关负载电感建模过程及混频器设计过程进行了详细分析,对整个射频前端芯片进行了测试,测试结果显示,射频前端核心电路在1.8V电源电压下工作电流为3.2mA,功耗为5.76mW;在高增益模式下,具有26dB的转化电压增益及8dB的噪声系数;在低增益模式下,输入1dB压缩点为-20dBm。A 2.4GHz low power low-IF RF frontend for wireless sensor networks was designed and implemented in a 0.18~m CMOS technology. The RF frontend consists of a variable gain low noise amplifier （VG-LNA） , a low pow- er folded Gilbert quadrature mixer and a divide-by-two circuit which generates the differential quadrature LO signals for the quadrature balanced mixer. The VG-LNA has the high gain mode and the low gain mode. The folded Gilbert active mixer was chosen to make up for the weakness on gain and noise figure of the common gate LNA. The design of the common gate LNA and the inductor modeling for this LNA, and the design of the mixer, were analyzed in de- tail, and the RF frontend was tested and measured. The measurement results showed that the frontend achieved the 26dB voltage conversion gain and the 8dB noise figure at the high gain mode, and the -20dBm input referenced l dB compression point at the low gain mode, while its DC operating current and power consumption were 3.2mA and 5.76mW under a 1.8V voltage supply.

关 键 词：射频前端 可变增益 低功耗 低噪声放大器(LNA) 折叠正交混频器 无线传感器网络(WSN) 

分 类 号：TP212.91[自动化与计算机技术—检测技术与自动化装置] TN851[自动化与计算机技术—控制科学与工程]