Low phase noise voltage-controlled oscillator

Abstract

The invention discloses a low phase noise voltage-controlled oscillator. The low phase noise voltage-controlled oscillator comprises a negative resistance circuit module, a difference coupling inductor capacitor resonant cavity and a source feedback inductor. The coupling inductance capacitor resonant cavity is used for improving an effective quality factor of the resonant cavity. Magnetic coupling between the source feedback inductor and the resonant cavity inductor is regarded as the feedback for increasing the amplitude of output signals of the resonant cavity, and the negative resistance circuit module adopts a current multiplexing structure to reduce power dissipation and remove deterioration of the phase noise by a second harmonic of a common mode node. The low phase noise voltage-controlled oscillator can effectively reduce phase noise.

Description

technical field [0001] The invention belongs to the technical field of radio frequency wireless receiver integrated circuits, and in particular relates to a voltage-controlled oscillator with low phase noise. Background technique [0002] A voltage-controlled oscillator is a module used to generate local oscillator signals in a communication system, and its performance directly determines the performance of the communication system. As a main performance index of the voltage controlled oscillator, the phase noise affects the sensitivity of the receiver and the adjacent channel interference of the transmitter. Therefore, it is particularly important to design a voltage-controlled oscillator with low phase noise for modern wireless communication systems. [0003] The implementation forms of voltage-controlled oscillators mainly include ring oscillators and inductor-capacitor voltage-controlled oscillators. Ring oscillators are mainly used to generate on-chip clock signals du...

AI Technical Summary

Problems solved by technology

However, due to factors such as skin effect and high loss of the substrate, the quality factor available for on-chip inductors is limited.

On the other hand, as the feature size of the CMOS process decreases, the power supply voltage decreases accordingly, and the output signal amplitude of the voltage-controlled oscillator also decreases, which makes the optimal design of low phase noise very difficult.

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