Low Phase Noise,wideband CMOS Integrated Voltage Controlled Oscillator Design

With the entry into the information society,wireless communication systems have gradually become the focus of people's attention and have received more and more attention.With the development of electronic communication technology today,high integration,excellent performance,wide application range,and stable working status have become important indicators for detecting the excellence of electronic products,while voltage-controlled oscillators are the core components of wireless transceivers for voltage-controlled oscillators.The performance indicators are increasingly stringent.Voltage-controlled oscillators are used to generate local oscillator signals and achieve signal channel selection and spectrum shifting.They are widely used in wireless terminal communications.For example,wireless telephones and navigation equipment,the phase noise performance and tuning range directly determine the entire communication system.The performance of the pros and cons or not.With the continuous development of CMOS technology and the improvement of radio frequency technology,people have gradually integrated the voltage-controlled oscillator and other circuits into the same chip during the research process of chip integration,but at the same time,people have to face The integrated inductor manufactured based on CMOS process has low quality factor and unfavorable phase noise.The nonlinear characteristics of the variable capacitor cause practical problems such as the instability of the PLL circuit on the integrated voltage controlled oscillator.Therefore,designing a low-phase-noise,wide-tuned frequency-domain VCO has very important practical significance today.This article begins with a general introduction to the important role and development history of voltage-controlled oscillators,and then the basic knowledge necessary to introduce,based on which some of the key technical indicators and performance of the design of voltage-controlled oscillators are analyzed.Based on the analysis of the phase-invariant linear time-varying model and phase-invariant voltage-controlled oscillator,a cross-coupled full-differential structure is adopted to ensure the reliability of the VCO and reduce common-mode noise;furthermore,the circuit structure is further improved.Improvements have been proposed on the tail current source to effectively filter out noise on the power supply and tail current sources.This article uses a self-improved switched capacitor array to ensure that the circuit has a wide tuning range,and also improves the performance of phase noise.In this paper,a planar spiral inductor with a symmetrical structure is used to improve the quality factor,so as to ensure the circuit has a superior phase noise performance.This paper designs an integrated voltage-controlled oscillator based on 0.13?m CMOS process.The simulation results show that the designed VCO has a center frequency of 5.22 GHz,a tuning frequency range of 4.77GHz~5.67 GHz and a phase noise of-107.161 dBc./Hz@1MHz,fully achieved the intended design.