基于DDS的低通滤波器设计与仿真

分析了几种经典滤波器特性,重点研究了DDS系统中低通滤波器的设计方法。根据DDS的结构特点和输出杂散频谱特性,结合滤波器技术指标使用了归一化法完成了一个九阶椭圆函数低通滤波器的设计,使其通带截至频率为120MHz、通带内最大衰减为0.2dB、在135MHz处阻带内最小衰减为66dB。通过Multisim10对其进行仿真后可以得出,使用此种方法设计的低通滤波器过渡带陡峭、幅频特性仿真良好,并且能够很好地满足预期的技术指标。

Design and simulation of low pass-filter based on DDS

Mainly analyzes the characteristics of several classical filters and focuses on the design method of low-pass filter.we are using normalized method and combinating with the filter specifications to completed a nine-order elliptic function low-pass filter design according to the structural and output of DDS spurious spectral characteristics.The filter has a cut-off frequency of 120 MHz and the passband ripple is less than 0.2 dB amd has a 66 dB attenuation in 135 MHz. The study of Multisim10 simulation shows that amplitude-frequency characteristic of the filter which has a steep transition zone is good and it can achieve the desired targets which using normalized method.