The Research And Design Of Low Power X-band CMOS VCO

With the development of new generation communication technology,satellite communications,and Internet of things,the research of communication system is effort to objectives of miniaturization,high integration density and low power.Silicon based Complimentary Metal Oxide Semiconductor(CMOS)process has attracted extensive attention worldwide.Voltage Controlled Oscillator(VCO)and Quadrature Voltage Controlled Oscillator(QVCO)are key devices of radio frequency transceiver systems,their technical indicators influence the overall performances of communication system.Meanwhile,oscillator takes a large part of power dissipation,in that the low power design of VCO has become a hot spot in the academic circle.This particle researches theoretical model,topologies and optimization method of VCO and QVCO.By using RF 130nm CMOS process,this work proposes one VCO and two QVCOs.The main works are as follows:1,The working principle and key performances of Class-C VCO are studied.With several implementation methods of Class-C VCO compared,this work uses amplitude control loop based on body bias technology to realize the automatic conversion of VCO working mode.After simulation and optimization of the Cadnece platform,the final layout simulation result shows that the VCO center frequency is 10.5GHz,relative frequency tuning range is 9%.This work draws 2.5mW DC power and the phase noise is-109dBc/Hz@1MHz offset.Achieved a good phase noise and tuning performance based on low power dissatisfaction.2,This paper proposes a low-power design method that combines the Class-C VCO core and bulk coupling technology,and derives the expression of the equivalent injection current of the bulk coupling network.The QVCO optimization results based on the derived expression show that the QVCO proposed in this design.The center frequency is 10.5GHz,the DC power consumption is 2.5mW,the relative frequency modulation range,the phase noise is-115dBc/Hz,FoM reaches 191.4dBc/Hz,which is more suitable for application scenarios that require low power consumption3,The working principle of QVCO is studied,this work applys series coupling network and transconductance linearized technique to design a high-precision low-phase-noise QVCO,which improves the voltage swing and reduces the impact of series coupling on phase error.QVCO simulation results show that the center frequency is 9.36GHz,the relative frequency modulation range is 5%,the DC power consumption is 8.36mW,and the phase noise is-119dBc/Hz@1MHz offset.The highest FoM is 198.5dBc/Hz.