一种用于数据驱动建模的信号发生器设计

提出了一种基于现场可编程门阵列（Field-Programmable Gate Array，FPGA）和ARM的直接数字式频率合成（DDS）信号发生器，产生频率可调的正弦波、三角波和方波信号，其中方波的占空比可调．阐述了信号发生器的体系结构，对波形产生的最小频率做了精确计算，同时对方波的占空比改变方式进行了设计和计算．在分析方波滤波电路后，计算确定了低通滤波器的电阻和电容值．最后对系统实现的效果做了频谱分析，结果表明，设置频率为主要分量，达到了设计要求．

Design of a signal generator for data-driven based modeling

Modeling of an industrial object based on data driven method needs signal generator as excita- tion source. This kind of system modeling requires signal source device being small in Size, high preci- sion, fast converting speed and flexible configuration. This paper provides a direct digital frequency synthesis （DDS） signal generator based on FPGA and ARM, which can generate sine wave, triangle wave and square wave. Both the frequency of wave and the duty ratio of square wave can be changed. The paper expounds the system structure of the signal generator makes a precise calculation on mini- mum frequency of waveform, at the same time, designs and calculates the way to change the duty ratio of square wave. Furthermore, it analyzes the filter circuit and has determined the value of resistance and capacitance in low-past filter by calculating. Finally, it has done the analyses on the effects of sys- tem implementation and achieved the design goals.