Study of High Performance DDFS Design Using Equi-Section Hybrid Approximation Method

• Main Authors: Jun-Yan Lai, 賴俊諺
• Other Authors: Shiann--Shiun Jeng
• Format: Others
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/9tx955

碩士 === 國立東華大學 === 電機工程學系 === 100 === Direct digital frequency synthesizer (DDFS) technology is widely used in signal generator, communication system and other fields due to the advantages of high-speed frequency switching and accurate frequency resolution. In this thesis, we propose a direct digital frequency synthesizer (DDFS) with an architecture based on Equi-Section Hybrid Approximation Method. In this structure, the first quadrant of the sinusoid wave is divided into a number of sections with equal width. This thesis is based on the use of hybrid technique to approximate the waveform in each section. The main research direction is to provide a new idea to combine the linear approximation with the parabolic approximation into the hybrid approximation. The approximation error of the linear approximation and parabolic approximation would be complementary. For analysis section, we utilize MATLAB for simulation and discover that Hybrid Approximation Method have better SFDR and MSE value than linear and parabolic approximation method.Taking 16 Equi-Section for example, the value of SFDR would be up to 90 dB when the first 2 Equi-Sections of Linear Approximation Method combine with the last 14 Equi-Sections of parabolic approximation method.