New Fractional-N Synthesizer and Performance of Phase Noise
Zhao Li · Modern Electronic Technique · 2004
FractionalN technology resolve the contradiction between frequency resolution and switching time in PLL synthesizer,but result in severe phase noise Traditional method of phase compensation needs high performance of digital component such as A/D,and has time delay,so it is difficulty to achieve it ΔΣ modulator has plastic function to noise,resultly N order ΔΣ modulatorused in FractionalN synthesizer can resolve the problem of phase noise,and accelerate the development and using of FractionalN synthesizer In the end the paper introduce the applid circuit of this new FractionalN synthesizer which was realized in GHZ frequency there ,and bring out the test performance of phase noise