A novel design of DTCXO with low phase noise

On the basis of the conventional method, the digital techniques for temperature compensation to VCXO always deteriorate the phase noise of the VCXO badly. And the essential cause for the deterioration of phase noise is the frequent variation of control voltage to the VCXO. This paper explores a novel non real-time digital technique for temperature compensation to the VCXO, which makes the compensation voltage more stable with slower and evener change. Lastly, the temperature-frequency performance of the DTCXO is improved greatly, and the phase noise is improved greatly at the same time.