一种应用高线性度OTA的具有宽调节范围的G_m-C滤波器(英文)  

A Widely Tunable G_m-C Filter Utilizing a High Linearity OTA

作　　者：刘银齐 叶茂 张扬[1] 赵公元 赵毅强[1] 

机构地区：[1]天津大学电子信息工程学院天津市成像与感知微电子技术重点实验室,天津300072

出　　处：《南开大学学报（自然科学版）》2017年第6期30-36,共7页Acta Scientiarum Naturalium Universitatis Nankaiensis

基　　金：Supported by National High-tech R&D Program(863 Program)(2015AA042605)

摘　　要：提出了一种改进的高线性度、宽调节范围的可调跨导运算放大器(OTA).其采用输入衰减和交叉耦合差分对两种线性化技术实现高线性度.此外采用源级退化电流镜结构对跨导值进行调节,实现了20倍的调节范围,同时保证了调节过程中维持相同的输入电压幅度.为了验证该OTA结构的有效性,设计了一个3阶低通滤波器.电路采用0.18μm SMIC CMOS工艺模型,仿结果显示,滤波器实现了从600 k Hz到10 MHz的线性调节,电流消耗为0.9-1 m A,其IIP3最高24.8 d Bm.An improved operational transconductance amplifier（OTA） with high linearity and wide tuning range is presented. Two linearization techniques, input attenuators and cross-coupled double differential pairs,are employed to achieve high linearity. Moreover, the source-degenerated current mirrors structure used to achieve the wide tuning range of the transconductance, guarantees the proposed OTA a 20 times relative tuning range without decreasing the input voltage-swing. A 3 rd-order low-pass filter（LPF） is presented to verify the effectiveness of the proposed topology of the OTA. Simulated with the 0.18 μm SMIC CMOS process, the post-layout simulation results showed that the LPF exhibits a linear tuning capability from 600 kH z to 10 MHz with a low current consumption of 0.9-1 m A. The in-band IIP3 is up to 24.8 d Bm.

关 键 词：跨导运算放大器 线性度 GM-C滤波器 调节范围 

分 类 号：TN713[电子电信—电路与系统]