中文摘要：

低通滤波器是DDS信号发生器的重要组成部分，其性能的优劣直接影响整个信号发生器的技术指标。使用一种全新的归一法，为DDS信号发生器设计了一个截止频率为120MHz的7阶椭圆型低通滤波器，并使用Multisiml0仿真软件对其进行仿真，仿真结果表明该滤波器幅频特性良好，可以达到预期的指标。

英文摘要：

Low-pass filter is an important part of the DDS signal generator, whose performance directly affects the technical indicators of the whole signal generator. This paper introduces a 7th order low-pass elliptic filter with the cut-off frequency of 120 MHz for the DDS signal generator with a new normalization method. Multisiml0 simulation shows that it has a good phase frequency characteristic and it can achieve the desired targets.