Research On CMOS Millimeter Wave Mixer Chip

In recent decades,the rapid development of wireless communication technology cannot be separated from the exploration and research of RF front-end chips.And the mixer module that plays the role of spectrum shifting is an indispensable part of the RF transceiver system.Meanwhile,silicon-based CMOS integrated circuit has attracted much attention due to its advantages of low cost and high integration.Therefore,this paper has conducted in-depth research on the silicon-based CMOS process mixer module.Firstly,this paper introduces and analyzes the basic knowledge of mixer,including its working principle,classification,performance parameters,etc.,which lays a certain foundation for the later design.Secondly,this paper conducts quantitative or qualitative analysis on the gain,linearity and noise of the mixer with general structure.To meet the requirements of different application,the optimized structure for different performance parameters is introduced,which further explores the mixer.Through the accumulation of previous knowledge theory,this paper studies and designs the mixer module of RF front-end chip for the fifth-generation mobile communication application.In order to meet the demand of high power input signal of transmitter system,a new linearized structure is introduced in mixer design.A parallel structure of common source and common gate is adopted to offset the third-order nonlinear term.Meanwhile,the linearity of mixer is further improved by using source degradation inductor.In addition,the transimpedance amplifier is adopted in the port of local oscillator?LO?to ensure the performance of mixer fluctuates within a reasonable range when the power of local oscillator changes.When the LO power is 0 dBm,IF frequency is 2.5 GHz,and the LO frequency is 9 GHz,its input 1dB compression point?IP₁dB?is 0.25 dBm,and the conversion gain is 0.13 dB.The simulation results also confirm the rationality of the linearization mechanism.Finally,this paper studies and designs the down-conversion mixer module of RF front-end chip for automotive radar systems.In order to meet the system's requirements for flicker noise corner frequency,noise figure and high linearity,a ring passive mixer structure is adopted.Then,the disadvantage of proposed structure in terms of conversion gain and port isolation can be solved by properly choosing the bias voltage,device size and layout.The mixer finally achieved the voltage conversion gain of-1.92dB and input 1dB compression point of 1.73 dBm when the RF frequency of 24.01 GHz and LO frequency of 24 GHz.Meanwhile,the double sideband noise figure?DSB NF?is 4.7 dB@10 MHz.In the single-module design,after the RF and LO input baluns are brought in,the measurement results of conversion gain is-3.9 dB,the input 1dB compression point is 3 dBm,and the isolation LO-to-RF port is better than 47 dB.After that,in the optimization design of the radar RF front-end system,the performance of the mixer in terms of noise figure,conversion gain and linearity are also optimized.Finally,the mixer achieves the conversion gain of-0.1 dB,the IP₁dB of 3.27 dBm and the DSB NF of 3.48 dB@10 MHz.Therefore,the ring passive mixer demonstrates unique advantages in the zero IF receiver system.