Research And Design Of CMOS Millimeter-wave Mixer

As a nonlinear system,the mixer is an indispensable device in the millimeter wave inverter transceiver.The ideal mixer is only to multiply the signals of the two input ports to achieve the purpose of mixing,but in practical applications,due to the impure influence of the input signal,the signal obtained by the frequency conversion will contain various interference signals,especially the image signal.The interference caused by the mixer often makes the mixer not get good results in actual use.A quadrature mixer is a good solution to the above problem.The input of the millimeter wave signal is processed using a quadrature signal to finally obtain an ideal signal.However,current quadrature mixers also face many problems such as amplitude and phase imbalance,so this paper focuses on the research of millimeter wave mixers,especially quadrature mixers.In response to the above problems,this paper does the following work.Firstly,the theoretical research on orthogonal signals and orthogonal networks is carried out,and the circuit is studied and elaborated by consulting the literature.Secondly,Gm-boost is incorporated into the mixer,and a similar structure is designed to improve The gain of the mixer reduces noise at the same time.Thirdly,this paper proposes an innovative circuit structure different from the traditional quadrature signal circuit,and designs a phase adjustment structure,which can adjust the circuit in real time to achieve the best balance.The organization of this paper is as follows.The second chapter details the basic principles,basic structure and indicators of the CMOS switching balanced mixer.After analyzing the circuit and formulating the formula,the theory of the mixer is clarified.Secondly,the third chapter introduces the principle of quadrature signals,generating circuits,improved methods and application scenarios,etc.,theoretically explains the importance of orthogonal signals in millimeter wave receivers and mixers.In Chapter 4,a 28 GHz quadrature downmixer is designed on a 65 nm CMOS process platform.This mixer applies the Gm-boost structure commonly used in low noise amplifiers to mixer designs to increase circuit gain while reducing circuit noise.The mixer achieves an 8 dB gain,a 12 dB noise figure,and an input 1 dB compression point of-5 dBm in the RF band 24-30 GHz,mid-range 1.8-4.4 GHz.The fifth chapter designs a 2.4 GHz mixer on a 110 nm CMOS process platform that uses a layout symmetry design and phase correction technology to achieve a highly balanced IQ signal.The technology is implemented in the low frequency band.After verification,it can also be applied to the millimeter wave band,which will lay the foundation for the improved design of the future millimeter wave IQ mixer.This work performs phase detection on the off-chip while designing the digital interface and the correction circuit on the chip to perform phase correction on the IQ signal.The final circuit achieves a 25 dB voltage conversion gain and a 6 dB noise figure in the 2.4 GHz range while achieving a 4° phase correction range.