带通滤波器矩形系数的理论分析与仿真

Theoretical Analysis and Simulation of Shape Factor of Bandpass Filter

依据频率映射公式,定量推导出带通滤波器矩形系数公式,揭示了带通滤波器kdB矩形系数就是其等效低通原型滤波器幅频特性曲线在kdB和3dB衰减处的归一化频率的比值、矩形系数与带通滤波器带宽无关等规律,并以常见的Butter-worth、Chebyshev滤波器为例,在ADS环境中对上述结果进行了仿真验证。

Based on the frequency mapping formula,the share factor of bandpass filter is derived quantitatively,it is revealed that the kdB share factor of bandpass filter is the ratio of normalized frequency of its equivalent low-pass prototype filter's amplitude-frequency characteristic curve at the attenuation of kdB and 3dB,and the share factor is independent of the bandwidth of bandpass filter.Taking common Butterworth and Chebyshev filters as examples,the above results of bandpass filter are verified by ADS simulation.