Development Of Signal Generator Bases On DDS

Signal generator is very important in modern electronic instruments. It is widely applied in many fields such as communication, navigation, radar, measure and control. Direct digital synthesizing is a new frequency synthesizing technology, which adopts phase increment controlled by digital. It has so many virtues such as high frequency resolving, fast frequency switching ability, continuous phase, low phase noise and integration easily for its digital operation that has been adopted wildly.After an analysis of the theory of popular signal generator and according to the target system, a signal generator with the brief structure and excellent performance is designed with adopting DDS, which is based on the AD company's DDS chip-AD9854. The system structure, the design of software and hardware and the way to realize the circuitry of the signal generator is analyzed in detail.The hardware of the signal generator consists of three blocks, those are signal generate module keyboard and LCD display module signal processing module. Software of the system mainly focuses on the design of C51 including control data processing communication, and so on. The corresponding PCB has been made and debugged. The whole circuit works well. The signal generator has many virtues, such as generating multiple sorts of signals, high precision and wide frequency width.