基于Visual Basic6.0IIR数字滤波器设计

Design of IIR Digital Filter Based on Visual Basic 6.0

详细研究了在Visual Basic 6.0环境下如何设计IIR数字滤波器。即利用发展相当成熟的模拟滤波器的理论、设计方法和严格的设计公式来设计滤波器。先根据给定技术指标求出模拟滤波器的传输函数,再转换成数字滤波器的传输函数。以低通,带通、带阻、高通数字滤波器为例,用脉冲响应不变法和双线性变换法两种转换方法来实现巴特沃斯、切比雪夫滤波器。利用Visual Basic设计了IIR数字滤波器并进行仿真,可随时调整参数对比滤波器特性,快速得到仿真结果,直观方便,极大地减轻了工作量,提高了工作效率。

In this paper, how to design IIR （Infinite Impulse Response） digital filters has been researched in detail Based on Visual Basic 6.Namely, we utilizes well developed analogue filter theory,method and rigorous formu.la to design digital filter. First the transfer function of analogue filter has been designed according to given technical parameters. After analogue transfer function has been derived, then transforms them into the digital filter. Second taking low pass, band pass, band stop, high pass digital filter for example, impulse invariance method and bilinear transformation have been used to implement Butterworth digital filter and Chebyshev digital filter. IIR digital filter based on Visual Basic 6,including Butterworth digital filter and Chebyshev digital filter, provides a direct and convenient tool for simulation. We can get filter character with adjusting parameters, also get simulation results quickly, which reduces burden and improves efficiency greatly.