Design Of Frequency Synthesizer Source On DDS

Frequency Synthesizer source is radar, communications and other modern large-scale electronic devices an indispensable and important component. Phase Noise indicators of performance of the system has a very important role, therefore, low phase noise, high stability, high reliability and a comprehensive source of frequency designed to be an important part to ensure system performance. Beginning in the 30's of the 20t" century, frequency synthesis theory is essentially one kind of frequency simulation (digital) computation technologies, which obtains a lot of high stability frequencies by implementing adding, reducing, multiplying, dividing (mixing, frequency multiplication, frequency division and so on) of the oscillating source's frequency, applies artificial or automatic control method (program control), realizes each type of frequency transformation and synthesizes each type of different signals.In reviewing the development history of the frequency synthesis based on direct frequency synthesis, indirect frequency synthesis and direct digital frequency synthesis of the working principle, performance analysis, implementation methods are summarized; to the rapid development in recent years, direct digital frequency synthesis technology The working principle, output characteristics, spurious performance are discussed.In analyzing the working principle of the signal generator, based on indicators of reasonably according to the system using DDS technology to AD9854 chip as the core, microcontroller chip AT89S52 as host and design a simple structure and excellent performance of the frequency synthesizer sources, and completed the system debugging and testing.