带宽可调的快响应时变低通滤波器

发布时间：2018-04-26 07:53

本文选题：低通滤波器 + 带宽可调　；参考：《山东大学》2017年硕士论文

【摘要】：滤波技术是信号处理中不可或缺的部分,设计具有优良性能的滤波器是一个关键问题。在实际生产生活中,大量的有用信息都承载于微弱的低频信号,低通滤波器的重要意义在于能够从噪声信号中提取有用的低频信号,因此低通滤波器的设计与发展至关重要。长期以来,人们致力于追求设计出具有易集成、低功耗、高精度等特性的滤波电路,并在测量、通信、仪器仪表等领域广泛应用。但在很多动态信号处理和测量应用中,当系统输入信号发生跃变时,边沿信号会含有丰富的频率成分,滤波器的输出信号容易跟不上输入信号的变化,人们希望设计的滤波器不仅能够有效滤波而且有较快的响应速度。然而对于传统的恒定参数的滤波器来讲,由于其通带恒定不变,很难同时满足以上的两项要求。在很多应用中,滤波系统的响应速度和精度同等重要,目前已经有一些快速滤波技术的理论与实现的研究。快速滤波技术具有广泛的应用需求,同时对于创新已经相当成熟的滤波理论和技术有重要意义。本文的研究目的是设计一种带宽可调的快响应时变模拟低通滤波器,解决恒定参数滤波器响应速度与有效除噪不能同时兼顾的问题,致力于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,对一阶、二阶时变低通滤波器理论分析,提出了时变低通滤波器参数变化规律,并借助Matlab仿真进行了验证。(2)设计出针对理想的连续单位阶跃和混有噪音的阶梯两种输入信号突变的检测电路。(3)设计了一种基于JFET的压控浮地线性可调的电阻电路。(4)在恒定参数低通滤波器的基础上设计出带宽阶跃可调和连续可调的快响应时变低通滤波器,就输入信号为理想的连续单位阶跃信号和混有噪声的阶梯信号分别对带宽可调时变低通滤波电路进行了实验研究,验证了能够实现兼顾有效除噪和快速响应的效果。仿真结果表明,本文所提出快速滤波技术方案是有效的,具有一定的工程应用价值。
[Abstract]:Filter technology is an indispensable part of signal processing, and the design of filter with excellent performance is a key problem. In practice, a lot of useful information is carried on weak low frequency signal. The significance of low pass filter is to extract useful low frequency signal from noise signal, so the design and development of low pass filter is very important. For a long time, people have been pursuing to design filter circuits with the characteristics of easy integration, low power consumption and high precision, and have been widely used in the fields of measurement, communication, instruments and instruments. However, in many applications of dynamic signal processing and measurement, when the input signal of the system jumps, the edge signal will contain rich frequency components, and the output signal of the filter will easily fail to keep up with the change of the input signal. It is hoped that the designed filter not only can filter effectively but also has a fast response speed. However, for the traditional constant parameter filter, it is difficult to satisfy the above two requirements because the passband is constant. In many applications, the response speed and precision of the filter system are equally important, and there have been some research on the theory and implementation of the fast filtering technology. Fast filtering technology has a wide range of applications and has important significance for the innovation of filtering theory and technology. The purpose of this paper is to design a fast response time-varying analog low-pass filter with adjustable bandwidth to solve the problem that the response speed and effective denoising of the constant parameter filter can not be taken into account at the same time. It is committed to the practical application of the theory and technology for reference. The main work in this paper includes: (1) in the field of simulation, the first and second order time-varying low-pass filters are theoretically analyzed, and the variation law of parameters of time-varying low-pass filters is proposed. The detection circuit for the mutation of two kinds of input signals with ideal continuous unit step and mixed noise is designed with the aid of Matlab simulation. A kind of voltage controlled floating-ground linear adjustable resistor circuit based on JFET is designed. Based on the constant parameter low pass filter, a bandwidth step harmonic and continuous tunable low pass filter with fast response is designed. In this paper, the continuous unit step signal with ideal input signal and the step signal with mixed noise are experimentally studied on the time-varying low-pass filter circuit with adjustable bandwidth, and the results show that both effective de-noising and fast response can be realized. The simulation results show that the proposed fast filtering scheme is effective and has certain engineering application value.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN713.4

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