Design of an arbitrary waveform signal generator

Signal generator plays a very important role in communication, electronic measuring instruments, electronic circuits, automatic control, radar and other electronic systems. Direct Digital Synthesis (DDS) technology can easily control the frequency of the signal for direct synthesis of waveforms. This paper designed a signal generator with the amplitude and frequency modulation by using AD9850 as frequency synthesizer and AT89S52 single chip microcomputer (SCM) as the core. Detailed design principle and idea are discussed. AD9850 of the DDS chip is used to generate the waveform. The frequency data of external input can be transformed to frequency phase control words of chip by simple parallel or serial communication interface with the single chip microcomputer. Amplitude modulation is realized by the AD7520 chip. The system is not only simple in structure, easy to implement, but also convenient and cheap. It has a theoretical and practical value.