摘要
针对无线传感网(WSN)对射频接收机低功耗的要求,提出了一种适用于WSN低中频接收机的一阶跨导电阻电容型(Gm-R-C)镜像抑制复数滤波器。该结构采用2个低功耗的全差动Gm单元和R-C负载对同相/正交输入信号进行低通滤波,频率变换则通过另外2个交叉耦合的差动Gm单元来实现。在详细分析一阶单元线性度、中心频率和调节范围的基础上,采用0.35μm CMOS工艺设计了一个4阶巴特沃斯复数滤波器,带宽为160kHz,中心频率为300kHz。在1%的器件失配下,仿真得到的镜像抑制比达到50dB,带内的输入3阶截取点功率为25.1mW,通带增益为18dB,输入参考噪声均方根电压值为35μV;在2.7 V电源电压下,滤波器消耗总电流仅为760μA。仿真结果表明,滤波器的各项性能均满足WSN系统的需求并具有较低的功耗。
A 1storder transconductancecapacitanceresistance （Gm-R-C） complex filter for image rejection in lowIF wireless sensor network （WSN） receiver is proposed to reduce the power consumption of radio frequency receiver in WSN. The proposed cell adopts two fully differential Gmcells with low power and RC loads to perform lowpass filtering for the input I/Q signals, while the frequency translation is realized by two additional differential Gm cells through directly crossadding relevant currents. Resistive source degeneration is adopted in the Gm cells to improve linearity. Based on the proposed 1storder cell, a 4thorder Butterworth complex filter with center frequency of 300 kHz and bandwidth of 160 kHz is designed using the 035 μm CMOS technology. Simulation results under 1% I/Q mismatch show that the filter achieves an image rejection ratio of 50 dB, an inband 3rdorder input intercept power of 25.1 mW, a passband gain of 18 dB, and an RMS voltage of input referred noise of 35 μV with current consumption of only 760 μA from a 2.7 V supply. All the simulated parameters achieve the system requirements of WSN with low power consumption.
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2013年第8期80-86,共7页
Journal of Xi'an Jiaotong University
基金
国家自然科学基金资助项目(61106027)
中央高校基本科研业务费专项资金资助项目(xjj2013088)
西安市科技计划资助项目(CX12187③)
关键词
无线传感网
复数滤波器
射频接收机
跨导单元
镜像抑制
wireless sensor network
complex filter
radio frequency receiver
transconductance
image rejection
