基于钟形函数分段非均匀补偿复调制的滤波研究

Filter Research Based on Piecewise Non-uniform Compensation Complex Modulated Bell Function

传统的IIR、FIR数字带通滤波器设计方法,滤波器性能受到阶数限制的影响.提出一种将具有不同中心频率的钟形函数进行复调制,再通过分段非均匀补偿后叠加,使其逼近较理想带通滤波器的设计方法.重点探讨了参数对带通特性的影响,以及分段非均匀补偿复调制的方法和步骤.开发了一个滤波仿真平台,用户界面简洁、实用.通过灵活设置钟形函数的形状参数τ、频率间隔Δw、叠加个数N等,可以设计出性能良好的带通滤波器.通过实例验证了该方法的有效性和实用性.

The performance of HR and F I R digital band-pass filter designed by traditional m e t h o d is limi-- ed by order number.In view of the p r o b l e m,n e w m e t h o d is put forward.Bell functions of different cen-ter frequencies are modulated and combined after non-uniform compensation, which can approach ideal characteristic of band-pass digital filter.The influence of parameters on bandpass characteristics and the method and steps of piecewise nonuniform compensation for complex modulation are mainly discussed. A simulation platform is developed.The user interface is simple and practical.The filter with excellent per-formance can be designed by appropriate setting of shape parameter frequency-shifting stack n u m b e r and so on.The validity and practicability of the m e t h o d is illustrated.