基于DDS和 FPGA的频率特性测试仪

针对传统频率特性测试仪价格昂贵、体积大、使用不方便等问题提出了基于DDS和FPGA的正弦信号频率特性测试仪。该测试仪由信号源模块、频率相位检测模块、数据处理与控制模块、显示模块4部分组成。该设计采用FPGA控制DDS芯片产生两路相互正交的信号，被测信号与之相乘，经滤波器后检测输出频率、幅度和相位，最后通过显示模块显示。实验结果证明，该频率特性测试仪设计正确可行，且硬件结构简单、体积小、重量轻，能广泛应用于正弦信号的测量，具有较高的应用价值。

Frequency characteristic tester based on DDS and FPGA

In view of the issues of the expensive price,big volume and inconvenient use of the traditional frequency charac-teristic tester,a sinusoidal signal frequency characteristic tester based on DDS and FPGA is proposed in this paper. The tester consists of a signal source module,frequency and phase detection module,data processing and control module,and display module. In the design of this tester,FPGA is used to control the chip DDS to generate two mutually orthogonal signals,which is multiplied with the measured signal for the detection of frequency,amplitude and phase of the measured signal through filter. The parameters of the signal are finally displayed by the display module. The experimental results show that the design of the fre-quency characteristic testing instrument is correct and feasible,has the advantages of simple hardware structure,small size and light weight,can be widely applied to the measurement of sinusoidal signals,and has high application value.