椭圆数字滤波器的设计-毕业论文(设计).doc

PAGE 毕 业 设 计 专 业： 通信工程 班级学号： 学生姓名： 指导教师： 二○一一年 六 月  天津职业技术师范大学本科生毕业设计 椭圆数字滤波器的设计 Design of Elliptic Digital Filter 2011年6月 精品毕业论文 摘 要 本论文的主要研究内容是数字滤波器的基本原理及设计理论，并探讨了椭圆数字滤波器的设计过程。数字滤波器的设计理论中，重点介绍了数字滤波器间接法设计过程以及典型的三种滤波器设计数学模型，分别是巴特沃斯滤波器、切比雪夫滤波器和椭圆滤波器。椭圆数字滤波器的设计过程，需要将给定的数字滤波器技术指标转换为相应模拟滤波器的技术指标，并通过频率变换转换为模拟低通滤波器的技术指标，构建模拟低通滤波器原型，再通过频率变换及双线性变换法或脉冲响应不变法得到所希望设计的椭圆数字滤波器。论文的最后部分，运用MATLAB仿真软件对椭圆数字滤波器进行了仿真。采用间接法得到了椭圆数字低通滤波器的频率响应特性曲线；采用直接法得到了椭圆数字带阻滤波器和椭圆数字带通滤波器的频率响应曲线，以及信号通过椭圆数字带通滤波器后滤除无用频率成分的滤波效果示意图。 关键词：数字滤波器；椭圆滤波器；MATLAB ABSTRACT The main contents of this paper is the basic principle and the design theory of digital filter, and it also contains the design of elliptic digital filter process. Digital filter design theory focuses on the indirect method of digital filter design process and the typical mathematical models of filter, they are butterworth filter, chebyshev filter and eliptic filter. Designing a elliptic digital filter, firstly, change the given digital filter specifications into the same type of analog filter’s specifications; secondly, convert to low-pass filter specifications, thirdly, build a prototype analog low-pass filter, finally, through the frequency transformation and bilinear transformation method or the same impulse response method design the desired digital filter. In last of this paper, I used MATLAB simulation software simulating the elliptic digital filter. Indirect method had been used in elliptic digital low pass filter’s design and got its frequency response curve. I also used the direct method designed elliptic digital band stop filter and elliptic digital bandpass filter, got their frequency response curve and the effect diagram of signals after elliptic digital band-pass filter. Key Words：Digital filter; Elliptic filter; MATLAB 目 录 MACROBUTTON InsertCrossReference TOC \o 1-3 \h \z \u 1 绪论 1 1.1 滤波器的发展 1 1.1.1 早期发展阶段 1 1.1.2 逐步发展阶段 2 1.1.3 快速发展阶段 2 1.2 数字滤波器概述 3 1.2.1 数字滤波器的研究背景与意义