Design and Improvement of a Frequency Synthesizer Based on PLL+DDS+PLL
Sun Ying, Yin Mei-liang, Teng Xie · 2017
A L-band high performance frequency synthesizer is presented for space TT&C channel.PLL+DDS+PLL structure is used to realize small step-size, high spectrum purity and low phase noise.Experimental result shows that its phase noise is better than -100d Bc/Hz@10KHz and its spurious suppression is better than -75dBc.But the additive spurious results co-frequency interference.Find out the case of cofrequency interference and propose corresponding countermeasures by analysis.