Design and implementation of 2.4 GHz carrier frequency FMCW signal generator
WU Ting-ga · Modern Electronics Technique · 2014
With the more and more wide application of FMCW radar,the performance requirements of FMCW signal generator is also more stringent. The DDS+PLL frequency synthesis technique was used to analyze the phase noise,stray loss and linearity performance indexes of the synthesizer. Based on this,a 2.4 GHz FMCW signal generator was designed,in which DDS chip AD9910 generates low frequency chirp signal,PLL chip HMC820LP6 CE as multiplier converts FM signal in low frequency to that in high frequency,and STM32 is taken as its controller. The experimental results show that the system has the characteristics of high frequency resolution,low phase noise,low stray loss,short frequency switching time,high linearity. Its proximal stray is-59.64 d Bc,remote stray is-55.02 d Bc,phase noise at 100 k Hz is-95.57 d Bc/Hz and at 400 k Hz is-118.38 d Bc/Hz.