.100 Msa / S Arbitrary Waveform Generator System Optimization And Improved Design

The Direct Digital Frequency (DDS) is a kind of advanced frequency synthesis technology. Arbitrary Waveform Generator (AWG) based on DDS, widely used in modern testing field, has a series of particular virtues, including high frequency resolutions, fast frequency switching and being apt to generate modulation waves.This thesis focuses on optimizations and improvements of system design on the basis of existent design, aiming at problems existed in the project"100MSa/s Arbitrary Waveform Generator". The main content of this thesis includes:1. Through analyzing and researching on the analog channel circuit, aiming at its defeats, a improvement design is presented. Firstly, according to analyzing the output signals'characteristics of frequency spectrums, single signal of DDS is used to treat, including filter and removing DC offset circuit. Then, the square generate circuit is improved to meet request of system by adding attenuator and eliminating DC offset circuit. Eventually, aiming at the defeats of power magnifier, author analyzes and simulates on power magnifier, finds the reasons resulting in problems, lastly, a solution method is presented in this thesis. By improving on the analog channel circuit, functions of instrument are perfected, performance of instrument is enhanced and debugging is easier.2. In addition, aiming at problems of analog modulation, such as low precision and wasting some hardware resources, some researches about technology of DDS modulation and theory of amplitude modulation are accomplished, a new plan of the realization based on DDS digital method in the FPGA is presented, analysis and validation also is performed, the results of experiment proves that this plan is feasible and valuable.