摘要
基于直接数字频率合成(DDS)原理,以单片机AT89S52为控制核心,结合现场可编程门阵列(FPGA),利用DDS集成芯片AD9851实现了在1 Hz～20 MHz的正弦信号发生器。AD9851输出的信号通过滤波、自动增益控制、功率放大后,在输出为50Ω负载的条件下,输出电压峰峰值可达10 V。此外,本系统还附有输出AM、FM、ASK、PSK、FSK等多种调制信号的功能。信号信噪比高,驱动能力强;系统复杂度低,易于在实验室中自制使用。
This system is based on the theory of direct digital synthesis（DDS）,adopting t he high performance chip of AD9851 that uses advanced DDS technology to generate perfect sine signals with the frequency range from 1 Hz to 20 MHz.The system t akes a single chip（AT89S52） as the control core,and combines the field program mable gate array（FPGA）.The sine wave generated by AD9851 takes through the AGC and PGA to achieve the steady output and the programming control of the treads o f the amplitude modulation（AM） signal.The voltage in peak-peak of the output can reach 10 V with 50 Ω load,having the function of AM singal output.FM sing al output.phase-shift-keying singal output,frequency swepting singal output. With a high SNR and driving ability,the system can be easily realized and used in laboratory.
出处
《实验室研究与探索》
CAS
北大核心
2011年第8期98-102,共5页
Research and Exploration In Laboratory
