The Design Of Signal Generator Based On DDS Technology

Signal generator is an important part of the test and measurement systems, it can producespecific parameter signal according to the requirements of users. It is a important role inscientific research, communications, national defense, precision industrial control, and manyother fields. Direct Digital Synthesizer technology is a new direction of the signal synthesis. Itis based on digital sampling and decomposition algorithm to realize the efficient digital storage,and it use phase feedback of control signals to realize complex frequency synthesis. Signalproduced by using DDS technology has low phase noise, high frequency resolution, frequencyband width and frequency switching speed, etc.In this paper, the main work is to develop a high frequency, high precision digital signalgenerator based on Direct Digital Synthesizer technology. The design of the signal generator isdivided into five units: the control unit, signal generating unit, signal processing unit, thehuman-computer interaction unit, power unit. Human-computer interaction unit issued acommand, the control unit makes the control signal generating unit in accordance with thecommand to generate signal, the signal processing unit to adjust and optimize the output signal.In this paper, the work includes: analysis of the principle of DDS, formulation design ofsignal generator, design and implement the hardware parts of the system, design and implementthe software parts of the system, evaluation and analysis the output signal of the system. Thisdesign based on DDS chip AD9854, using STM32F103VE chip as the core of the control unit.Using C language to develop the main monitoring program and signal process. Using Pythontools to implement visual interface. Low-pass filter circuit and multistage amplifier circuit wasused to optimize the signal. Verified, the output of the signal generator meet pre-set indicators.