Design Of RF Low Power And High Linearity Mixer And Wideband Voltage Controlled Oscillator

In recent years,with the rapid development of wireless communication technology,there are more and more application scenarios of RF transceivers.RF front-end chip is the basis of wireless communication.The performance of RF transceiver directly affects the communication quality of terminal.It is more and more difficult to design high performance RF transceiver because of the continuous transformation of technology and application scenarios,as well as the serious skin effect and parasitic effect at high frequency.As the key components of RF transceiver,the high performance mixer and voltage controlled oscillator have very important research value.This Paper first introduces the mixer at home and abroad and the research status of voltagecontrolled oscillator and sums up the paper research significance,and then the mixer and the theory of VCO,common topology structure and the analysis method,through the analysis of the advantages and disadvantages of all kinds of circuit structure,guidance,and optimize the subsequent-band low power consumption and high linearity passive mixer and broadband voltage-controlled oscillator design.A L-band passive mixer with low power and high linearity was designed based on 0.25 Ga As p HEMT technology,schematic/layout design,simulation,flow chip and chip test were completed.The mixer consists of an on-chip passive balun,a local oscillator drive amplifier and a passive double-balanced mixer core.When the local oscillator input frequency is 800MHz～1000MHz and the RF input frequency is 960MHz～1080MHz,the corresponding intermediate frequency output band is 0.1MHz ～250MHz.The chip size is 3.1mm×2.1mm×0.1mm.The test results show that the frequency conversion loss is 9.5d B,the input 1d B compression point is 19 d Bm,the power consumption is 0.24 W,the single side band noise coefficient is less than 11 d B,and the isolation degree between the three ports is above 27 d Bc.This mixer chip mainly through the passive mixing core peripheral local oscillator drive amplifier optimization design,improve the linearity of the mixer,by optimizing the passive balun on the chip to reduce the frequency conversion loss of the mixer,and the use of dual balance structure to improve the isolation between ports.Based on GF 45 nm SOI technology,a wide band voltage controlled oscillator(VCO)was designed with cross-coupling structure.In this VCO,the linearity of the transconductance of the transistor was improved by increasing the negative feedback resistance of the source pole,so as to reduce the influence of pipe noise on VCO phase noise.The Q value of on-chip passive inductor is optimized,and the phase noise performance is further improved.Completed VCO schematic/layout design,pre/post imitation,layout area is 0.4mm×0.5mm.The simulation results show that the output frequency band of VCO is 5.64～6.75 GHz,the phase noise is-120.7～-113.62 d Bc/Hz@1MHz,and the total power consumption of the circuit is 3mW under the supply voltage of 1V.