基于FPGA的直接数字合成器的设计

Design of direct digital synthesizer based on FPGA

介绍了直接数字合成器(DDS)的基本组成及工作原理,采用QUARTUSⅡ软件提供的模块和VHDL语言自行设计的寄存器,实现了现场可编程门阵列(FPGA)的相位累加器和波形存储表的设计。通过频谱分析研究了DDS的输出频谱,分析讨论了引起输出杂散的原因及改善杂散的方法。研究结果表明,该设计具有较高的实际应用价值。

The structure and principle of direct digital synthesizer （DDS） were introduced. Adopting the module of QUARTUS II and the register of VHDL, the field programmable gate array （FPGA） phase accumulator and waveform storage table design were achieved. The output spectrum of DDS from frequency was analyzed, the reasons of the output spur and the methods for improving spur were discussed. The results of research show that the design has more high practical value.