The design of high performance X-band frequency synthesizer based on DDS and PLL

Abstract

In this paper, an X-band frequency source based on DDS and PLL whose output is 11.75~12.25GHz is developed. The DDS can be controlled through FPGA and PC. According to fast-locked analysis, low spurious analysis and low phase noise analysis, the optimal loop parameter is selected upon MATLAB simulation. Then low phase noise, frequency agile and low spurious are achieved. On the basis of the test results, the best frequency switching time is less than 10us, the phase-noise is better than -104dBc/Hz@10kHz, the spurious are better than -50dBc and step size 2.5kHz.