变参数无漂移有源低通滤波器

发布时间：2018-05-15 17:42

本文选题：有源低通滤波器 + 无漂移　；参考：《山东大学》2015年硕士论文

【摘要】：滤波是信号处理中一个重要的概念,设计一个性能良好的滤波器也就成了关键问题。滤波器是一种选频装置,可以让频率在通带内的信号分量通过,而极大地衰减其他频率成分。长期以来,在科学与生产活动中,由于低频微弱信号承载了大量的基础信息,低通滤波器被广泛应用于噪声环境下的信息获取和抗干扰设计。在直流通道中引入低通滤波器,是抑制噪声,尤其是工频噪声的有效方法。然而,无源RC滤波器只能实现极点在负实轴上且为单根的一类特殊传递函数,不能适应多样性的工程要求。因此,有源RC低通滤波器是目前研究最多的低频滤波系统。然而在引入有源RC滤波器时,信道中会引入由有源部件产生的新的附加漂移。在海洋监测、地质勘查和生物医学等领域的低频微弱信号传感、检测系统和高精确度仪器仪表中,系统的灵敏度通常会达到uv甚至nv量级,这时的附加漂移是跟噪声一样严重的问题。在设计滤波器时,我们希望滤波器在通带内具有好的频率特性,同时响应速度快。在很多应用中,滤波系统的的响应速度是和精度同样重要的指标。然而,传统的滤波器实现方法不能满足这样的特性。本文的研究目的即建立原理上无信道附加漂移的快响应有源变参数低通滤波系统理论和实现方法,能够为实际应用提出可供参考的理论和技术。本文所做的主要工作包括：(1)在模拟领域,提出了一种任意阶无漂移全极点有源低通滤波器,给出电路结构进行原理分析,通过仿真验证,与传统有源低通滤波器相比较,证明该滤波器具有低漂移特性。(2)在无漂移有源低通滤波器的基础上提出变参数滤波器,使滤波器的参数能随时间发生变化,从而使响应速度得到较大的提高。仿真结果表明,本文所提出的方案是有效的快速滤波技术,具有一定的工程应用价值。本文所用的仿真是借助Pspice和Multisi n仿真工具得出的。
[Abstract]:Filtering is an important concept in signal processing. Designing a filter with good performance becomes a key problem. A filter is a frequency-selecting device that allows the signal components of the frequency in the passband to pass through and attenuate other frequency components significantly. For a long time, in science and production activities, low pass filter is widely used in information acquisition and anti-jamming design in noise environment because of the low frequency weak signal carrying a large amount of basic information. It is an effective method to suppress noise, especially power frequency noise, by introducing low pass filter in DC channel. However, passive RC filter can only realize a class of special transfer functions with poles on negative real axis and single root, and can not meet the engineering requirements of diversity. Therefore, active RC low-pass filter is the most studied low-frequency filter system. However, when the active RC filter is introduced, the new additional drift generated by the active component will be introduced into the channel. In the fields of ocean monitoring, geological exploration and biomedicine, low frequency weak signal sensing, detection system and high precision instrument, the sensitivity of the system usually reaches the level of UV or even NV. The additional drift is a problem as serious as noise. In designing the filter, we hope that the filter has good frequency characteristics in the passband and high response speed. In many applications, the response speed of the filtering system is as important as the accuracy. However, the traditional filter implementation method can not satisfy this characteristic. The purpose of this paper is to establish the theory and implementation method of fast response active variable parameter low pass filtering system without channel additional drift in principle, which can be used as reference theory and technology for practical application. In the field of simulation, this paper presents an arbitrary order drift-free all-pole active low-pass filter. The principle of the circuit structure is analyzed and compared with the traditional low-pass filter by simulation. It is proved that the filter has the characteristic of low drift. (2) based on the no-drift active low-pass filter, a variable parameter filter is proposed, which makes the parameters of the filter change with time, and the response speed is greatly improved. The simulation results show that the proposed scheme is an effective fast filtering technique and has certain engineering application value. The simulation in this paper is obtained by Pspice and Multisi n simulation tools.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN713.4

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