A Design Of Arbitrary Waveform Generator Based On DDS

The importance of the signal generator is self-evident in the electronics field. As a research person, we must not only know how to use a signal generator, but also to understand the principles of its composition. Signal generators from 1980s’ several hundred MHz analog signal generator waveform to today’s output of up to several GHz frequency waveform has improved a lot and the researchers can not do this without the tireless efforts. But this is still far from meeting the needs of education and research, and signal generator which can produce arbitrary waveform is still the main trends of scientific research.The main purpose of this paper is to design an arbitrary waveform generator(AWG). Given Tektronix and Agilent signal generator which the school purchased are too expensive and too many features and complicated for the student learning, the result often is that many students are familiar with the operation of the instrument, and ignoring the signal generator is a true role as an excitation source measurement and it also caused a waste of school resources, the need of a AWG which is suitable for student teaching and does not require much functionality is so urgent. This generator which is easy to use can enable students to focus on the role of the signal generator and the price is cheap. Therefore, we design a signal generator with a touch screen, 100 MHz can produce sine, square and triangle wave to 10 MHz, to achieve the basic frequency shift keying, phase shift keying, and can produce any desired waveform and other features, easy to operate, easy to customize to meet the needs of current teaching.The system is mainly based on direct digital frequency synthesis(DDS), integrates high-performance digital signal processor TMS320F2812, DDS proprietary chip AD9854, AD9708 analog-digital converter chip and 7 inch TFT touch screen, has a lower cost, convenience and other advantages. TMS320F2812 is the system’s main chip, the main role is to complete digital signal processing, control and other input and output devices, and communications functions. Dedicated DDS chip AD9854, in this system is mainly responsible for generating high-frequency, high-resolution sine, square, triangle wave and modulated signals output signal. AD9708 DAC’s role is to generate arbitrary waveform signal processed by DSP, and arbitrary waveform output by the AD9708. The purpose is both TFT touch screen can be used as an input device, through the touch screen to draw arbitrary waveform output can also be used as a display device, showing the various parameters of the system to produce the waveform data.The application of this design is practicable and can achieve the purpose of the original purpose. The AWG which is general, practical and easy to customize can meet the needs of teaching and research.