Research On K-Band CMOS LC Voltage-Controlled Oscillator

With the increasing demand of wireless communication data transmission speed,millimeterwave band has attracted the attention of researchers because of its abundant channel capacity and excellent data transmission ability.In this band,LCVCO has the characteristics of low noise and low jitter,so it is widely used in K-band signal sources.This paper studies the analysis of basic theory,design of circuit structure and the optimization of on-chip passive devices and presents two signal source circuits,dual feedback current-reuse voltage-controlled oscillator and injection-locked phase shifter.In millimeter-wave VCO,the trade-off between phase noise and power consumption is always a challenging issue.In order to solve this problem,a K-band VCO based on double feedback technology implemented in 55 nm CMOS technology is proposed.In this design,the feedback of stacked transistor is changed to the S2G,reducing the operating time of the triode area within one cycle.In addition,a reverse coupling transformer is designed to realize the combination of the two feedbacks.By designed routing,the two differential ends of the transformer are coupled in opposite directions,enabling both transistors to provide negative resistance respectively to start oscillation.This design is based on 55 nm CMOS process,the core area is only 0.046mm 2,and power consumption is 3.7mW.The measurement results show that the phase noise of the VCO is about-108.45 dBc/Hz at the frequency offset of 1MHz,and the tuning range is about 4%.The calculated FOM is up to 190 dBc/Hz.The existing injection-locked phase shifters all require a off-chip LO signal,which reduces the chip integration.To solve this problem,a signal generation phase shifter based on 55 nm CMOS technology and injection-locked phase shifting is proposed in this thesis.This design realizes fully integrated on-chip injection-locked phase shift by injecting the signal of one VCO core into another VCO.This phase shifter is not only capable of phase shifting,but also provides an adjustable frequency signal.In addition,we also improve the existing small-signal model and propose its large signal model.Through theoretical analysis,we show that 60° continuous phase shift can be achieved in the injection-locked phase shifter at around 23GHz.The core area of the proposed signal generator phase shifter is 0.078mm 2.The measurement results show that the frequency range is 2.3GHz(22.5～24.8 GHz),the minimum output power is 5.2dBm,and the phase noise is about-83dBc/Hz.The maximum continuously adjustable phase is 45.5°.