Ultralow phase noise frequency source circuit and manufacturing method thereof

Abstract

The invention discloses an ultralow phase noise frequency source circuit which comprises a reference circuit, a low phase noise frequency multiplier circuit and a phase cancellation circuit. The phasenoise of signals comprises related phase noise and random phase noise; and the ultralow phase noise frequency source circuit can counteract the related phase noise to optimize the phase noise of thesignals. By generating a reference signal with low phase noise, performing frequency multiplication on the reference signal to generate a radio frequency signal with low phase noise, modulating an original signal and a phase noise signal which is obtained after the radio frequency signal is demodulated and delayed to remove the related phase noise, the purpose of optimizing the phase noise is realized. By a way of increasing a phase noise index through phase cancellation, the 10dB index is increased again on the basis of the traditional low phase noise frequency source.

Description

technical field [0001] The invention relates to the communication field, in particular to an ultra-low phase noise frequency source circuit. Background technique [0002] The existing low phase noise synthesis technology mainly uses the traditional diode nonlinearity to generate rich harmonics, and then selects frequency points and low phase noise amplification through filters to achieve ultra-low phase noise signal synthesis. This technology is mainly limited by the phase noise index of the existing crystal oscillator. The optimal index that can be achieved is that the reference signal is theoretically deteriorated by 20logN (N is the number of frequency multiplications), so the phase noise index will be limited by the phase noise of the existing crystal oscillator. Contents of the invention [0003] The purpose of the present invention is to overcome the deficiencies of the prior art, provide an ultra-low phase noise frequency source circuit, realize the ultra-low phase ...

AI Technical Summary

Problems solved by technology

This technology is mainly limited by the phase noise index of the existing crystal oscillator. The optimal index that can be achieved is that the reference signal deteriorates by 20logN according to the theory (N is the number of frequency multiplications), so the phase noise index will be limited by the phase noise of the existing crystal oscillator.

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