zyyang
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good evening everyone, recently i have encountered a problem, my Integer-N FS have an excellent phase noise performance, but its spur are bad, i think if we only consider the design improvements, the ways to improve the spur are followed:
1 make the fully differential charge pump, may be the matching will be well, but the random offset may worsen spur.
2 changing the loop filter structure as Mr. Adrian Maxim, but his method is to use the ICO, what about the LC_VCO? How i realize the addition of two voltage? and the gm convertor may worsen the phase noise?
3 the discrete time loop filter as Mr. Benyong Zhang in JSSC, i think this is the easist way. and i am studying, may be the stability will be a bug?
After all , wish all of your suggestion about this subject, you'd better talk about some ideas in IEEE JOURNAL.
REGARDS!
1 make the fully differential charge pump, may be the matching will be well, but the random offset may worsen spur.
2 changing the loop filter structure as Mr. Adrian Maxim, but his method is to use the ICO, what about the LC_VCO? How i realize the addition of two voltage? and the gm convertor may worsen the phase noise?
3 the discrete time loop filter as Mr. Benyong Zhang in JSSC, i think this is the easist way. and i am studying, may be the stability will be a bug?
After all , wish all of your suggestion about this subject, you'd better talk about some ideas in IEEE JOURNAL.
REGARDS!