摘要
直接数字频率合成(DDS)是一种可以实现多种调制的新的频率合成技术。调频和调相统称为角度调制。调频是根据调制波的幅度去改变载波的频率;调相是根据调制波的幅度去改变载波的相位。本文在数字电路中实现了模拟调制,大大提高了可移植性和可控性。文章首先介绍了用DDS实现FM、PM调制的基本原理,然后在通用的基带调制硬件平台基础上,给出了一种基于DSP和FPGA实现FM、PM调制的具体方法。最终通过DAC电路,在输出端口得到最终的输出,并且在频谱仪上得到了设定的满足设计要求的所频谱。
Direct Digital Synthesis （DDS） is a new frequency synthesis which can achieve a variety of modulation. FM and PM are collectively called angle modulation. FM change the frequency of the carrier based on the amplitude of modulation wave; PM change the phase of the carrier based on the amplitude of modulation wave. This paper realize analog modulation in digital circuit,greatly increased the portability and controllability. At first,this paper introduces the basic principles which is based on DDS,then introduces the specific methods of the achievement of FM/PM which is based on common base-band modulation hardware which is build up by DSP and FPGA. Finally get the final output by the output port of DAC,then get the spectrum which is meet the design requirements on the spectrum analyzer.
出处
《电子测试》
2010年第10期64-66,83,共4页
Electronic Test
