用AD9912实现的多功能低相噪信号发生器

Multifunctional Low Phase Noise Signal Generator Based on Digital Frequency Synthesis Technology

随着无线电通信技术的发展,移动通信、雷达等系统对信号源的要求越来越高,而频率范围宽,高稳定性、相位噪声低的信号源一直是通信领域研究热点,传统的信号源已经无法满足当前电子技术领域研究的需求。为了研究多功能低相噪信号发生器,采用了直接数字频率合成(Direct Digital Synthesizer,DDS)技术,DDS具有生成频率范围宽、频率分辨率高的特点,广泛应用于信号源电路中[1]。基于DDS的多功能低相噪信号源,能够支持点频和扫频输出两种模式,产生1 Hz~400 MHz的正弦信号,实现频率范围宽、高稳定性、相位噪声低、控制方便的信号输出。经测试,200 MHz时,频偏100 kHz,相位噪声为-60.14 dBc/Hz。结合DDS技术与单片机技术实现DDS多功能信号源,控制方便,便于观察,产生的正弦波信号波形光滑、相位噪声低,可通过进一步提高频率和幅度,加入调相功能,应用于相关设备中。

With the development of radio communication technology,mobile communication,radar and other systems have higher and higher requirements for signal sources,and the wide frequency range,high stability,low phase noise signal sources have been a research hotspot in the field of communication;the traditional signal sources have been unable to meet the current research needs in the field of electronic technology.In order to study the multi-functional low-phase noise signal generator,direct digital frequency synthesis(DDS)technology is adopted to design a multi-functional low-phase noise signal source based on DDS,which can support point frequency and sweep frequency output,and produce 1 Hz~400 MHz,with wide frequency range,high stability,low phase noise and convenient control.After tested,at 200 MHz,the frequency is 100 kHz and the phase noise is-60.14 dBc/Hz.