【作者】 刘鑫；

【导师】 何海珍；

【作者基本信息】 湖南大学 ， 信息与通信工程， 2013， 硕士

【摘要】 随着集成电子电路技术的飞速发展，全集成连续时间模拟滤波器作为集成电路中的一个重要应用，成为国内外微电子、电路与系统学界研究的热门课题。基于电流差分跨导放大器(CDTA)的滤波器具有工作电压低、动态范围大、线性度好、高速、低功耗和结构简单等特点，成为众多滤波器研究设计中最具潜力的一类。本文主要研究了电流差分跨导放大器及其在连续时间模拟滤波器方面的应用。文章首先介绍了滤波器的一些基本概念、类型和发展概况，概述了电流差分跨导放大器及其应用的研究进展。基于对电流模式电路、电流差分跨导放大器和滤波器的研究，提出了一种新的电流差分跨导放大器电路，以电流差分跨导放大器为基本单元结合信号流图法，提出了两种连续时间双二阶模拟滤波器。论文的主要工作和创新如下：(1)提出了一种基于全NMOS复合晶体管的电流差分跨导放大器电路。电路具有低输入阻抗，低电源电压和功耗，较小的失调和漂移，良好的高频特性和低噪声特性等优点。为了验证所提电路的正确性，对电路的端口特性、输入输出阻抗进行了理论分析，PSpice仿真验证了电路的正确性。(2)提出了一种单片CDTA实现的三输入单输出双二阶多功能滤波器。电路由一个CDTA基本模块、两个电容和两个电阻组成。电路结构简单、无源元件少，通过改变输入信号的接入点，能实现二阶滤波器(低通、带通、高通、带阻、全通)的全部功能。(3)提出了一种由信号流图法综合实现CDTA双二阶滤波器的设计方法。结合CDTA的端口特性将二阶低通滤波器的信号流图演变为双二阶滤波器的信号流图，然后利用CDTA构建的基本电路模块来模拟信号子流图，实现由信号流图到双二阶滤波器电路的转变。利用该设计方法提出了一种多输入多输出的双二阶滤波器。所提出的滤波器电路，灵敏度低，固有频率ω0和品质因素Q独立可调。通过PSpice软件对提出的滤波器进行仿真，结果与理论分析吻合。更多还原

【Abstract】 In recent years the integrated circuit technology has a significant development.As one of the important application of integrated circuit, the integratedtime-continuous analog filter is also tend to be a hot topic about microelectronicsand circuit&system both in domestic and overseas. The filter based onCDTA(Current Differencing Transconductance Amplifier) has the characteristics oflow work-voltage, extensive range of dynamic, good linearity, high speed, lowconsumption, simple construction. As all of the above advantages, this filter has themaximum potential in filter design.This dissertation mainly focuses on the study of the CDTA, and the study ofbiquad filter based on CDTA. Firstly it introduced the concept, type anddevelopment of filter and the development situation of CDTA. Refer to the researchof current mode circuit, CDTA and filters, a new realization of CDTA is represented.Moreover the paper also came up with some time-continuous biquad filters which arebased on CDTA and the method of signal flow graph. The main innovations andworks about this dissertation are as follows:(1)An all NMOS transistors based current differencing transconductanceamplifier is designed. The proposed circuit has the advantages of low impedance,low source voltage, low consumption, little imbalance and drifting, bettercharacteristics in high frequency, low noises. To testify the correction of theproposed construction, a theory analysis of port char acteristics and input impedance&output impedance is made. And PSpice is used to simulate these parameters. Allthe simulation is show that the proposed circuit and its performance are correct.(2)Single CDTA implement a three-input single-output mult ifunction biquadfilter is presented. The circuit consists of single CDTA, two capacitances and tworesistors. And compared with other single CDTA based biquad filters, the proposedcircuit possesses the simple constructions, the minimum using of passive compo nent,and it can realized all biquad filter function(Low Pass, Band Pass, High Pass, BandElimination, All Pass) by altering the input current terminals properly.(3)Signal flow graph synthetically implement the multifunction filter based onCDTA is presented. The method is that, as with the principle of CDTA, second low pass filter signal flow is transferred to biquad filter signal flow. Then used the basiccircuit module based on CDTA to simulate signal flow sub-graph. That is realizedthe transformation from signal flow graph to biquad filter. By this method, amulti-input multi-output biquad filter is proposed. All the above presented filter hasthe advantages that the nature frequency ω0and quality factor Q can beelectronically tuned, and the sensitivity of the filter is very low. PSpice has used tosimulate these circuits, and simulation results confirmed the theory.更多还原