The technology of DDS-driven PLL is introduced and a new scheme of frequency synthesizer which is suitable for SW SFH/MFSK
System is presented in this paper. Based on the special requirement of SW communication, a model of the scheme is given and
the results show that the frequency synthesizer has small frequency insteval (≤0.1 Hz), short switch pierod (<200 ms) and
high frequency stability as crystal oseillator.
Key words frequency synthesizer - frequency inteval - switch pierod - FH communication
Supported by the National Nature Science Foundation of China and the Advanced Research Foundation of National Defence
Gan Liangcai: born in 1941, Professor