Application of DDS+PLL Technology in C-band Frequency Synthesizer
Tao Xu · Modern Electronics Technique · 2008
A kind of design scheme about a concrete Cband fine resolution frequency synthesizer is proposed in this paper.This scheme based on the structure which integrated Phase Lock Loop(PLL) frequency synthesizing with Direct Digital Frequency Synthesizing(DDS),generating the needed signal with DDS impelling PLL.The designed frequency range is from 5.02～5.38 GHz,and the step range of frequency is 1 kHz.The focus of this paper is the hardware implementation including system design,circuit design of key module and test result of the whole system.Meanwhile,the paper gives a few improvements referring some familiar problems about the system while debugging.The last measured results show the performances of high purity spectrum,low phased noise,low spurious level,and satisfy the requirements for the practical system.