Low-noise crystal oscillator based on multiple resonators and implementation method thereof

Abstract

The invention discloses a low-noise crystal oscillator based on multiple resonators, and mainly solves the problems that an existing crystal oscillator reduces background phase noise of oscillator output signals, product debugging difficulty is increased, and batch production is not facilitated. The crystal oscillator comprises a filter circuit connected with an external voltage-stabilizing powersupply; a transistor amplifier, wherein the collector electrode of the transistor amplifier is connected with the power supply circuit; a main vibration frequency selection loop and a feedback capacitor which are connected with a base electrode of the transistor amplifier; a crystal frequency selection feedback circuit which is connected with the feedback capacitor; an LC parallel resonance network which is connected with the main vibration circuit and the feedback capacitor; and a crystal filter circuit which is connected with the transistor amplifier. According to the invention, the circuitfrequency selection characteristic and the circuit on-load Q value can be effectively improved, the phase noise of the near-load frequency band of the oscillation signal is reduced, the high-Q crystalfrequency selection feedback circuit is arranged at the output of the main oscillation emitter, the narrow-band frequency selection characteristic of the crystal resonator is fully utilized, and thesignal phase noise index of the far-load frequency band is improved.

Description

technical field [0001] The present invention relates to the technical field of quartz crystal oscillators, in particular to a multi-resonator-based low-noise crystal oscillator and its implementation method. Background technique [0002] With the continuous development of modern communication and radar technology, the phase noise of frequency source has become one of the key indicators of system performance. As an excellent signal source, crystal oscillators provide reference frequency signals for many electronic equipment such as instruments, communication equipment, and radar systems. They are key core devices such as instrumentation, communication equipment, and radar systems. The main factor limiting the performance of the entire electronic system. [0003] Such as figure 1 As shown, when the quartz resonator used is the overtone response waveform diagram of the overtone crystal, the means to reduce the phase noise of the crystal oscillator is to increase the signal-to...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a multi-resonator-based low-noise crystal oscillator and its implementation method, which mainly solves the problem of reducing the background phase noise of the oscillator output signal in the existing crystal oscillator, but the additional cost is high and the miniaturization It is more difficult, and the difficulty of product debugging is increased, which is not conducive to the problem of mass production

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