Low-phase noise reference source

Abstract

The invention discloses a low-phase noise reference source. The low-phase noise reference source includes a phase-locked 100MHz signal source, a first frequency multiplier, a first mixer, a first loop filter and an ultra-high frequency voltage controlled surface acoustic wave oscillator; the first frequency multiplier performs frequency multiplication on stable 100MHz signals generated by the phase-locked 100MHz signal source so as to generate ultra-high frequency signals the frequency of which is same with the that of the output signals of the ultra-high frequency voltage controlled surface acoustic wave oscillator; the first mixer performs phase discrimination on the ultra-high frequency signals generated by the first frequency multiplier and signals outputted by the auxiliary path signal output end of the ultra-high frequency voltage controlled surface acoustic wave oscillator so as to generate first phase discrimination voltage; the first loop filter filters the first phase discrimination voltage so as to generate first voltage controlled voltage; and the ultra-high frequency voltage controlled surface acoustic wave oscillator outputs stable ultra-high frequency signals through a main path signal output end according to the control of the first voltage controlled voltage, wherein the stable ultra-high frequency signals are adopted as the output signals of the low-phase noise reference source. According to the low-phase noise reference source of the invention, the phase noise index of the reference source on higher frequencies can be improved.

Description

technical field [0001] The invention relates to the technical field of frequency synthesis and frequency source phase noise performance. More specifically, it relates to a low phase noise reference source. Background technique [0002] Phase noise is a random phase fluctuation that distorts the linear variation trend of the frequency source phase. It is an important performance parameter in radar, radio communication, navigation and positioning and other application fields, and has a significant impact on the performance of communication systems and weaponry. Often become the limiting factor of system performance. In order to ensure and improve the performance of communication systems and weaponry, reducing the phase noise of frequency sources has become an important direction in current frequency source design. [0003] At present, there are mainly the following implementation methods for frequency sources: direct frequency synthesis, phase-locked frequency synthesis, dir...

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Problems solved by technology

[0008] The purpose of the present invention is to provide a reference source with low phase noise to solve the problem that the phase noise index of the existing reference source is difficult to improve at higher frequencies

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