Research On Modeling Technology For Passive Devices Of Millimeter Wave

With the increasing requirements for data rate of wireless communication systems,the upcoming 5G communication era is becoming more and more remarkable.And RF(Radio Frequency)/mmWave(millimeter-wave)on-chip transceivers,as an important hardware support part of 5G communication systems,has caused a boom in research and design in academia and industry.Compared with traditional III-V family compound technology,the silicon-based technology has several advantages such as low-cost,low-power consumption and easy to integrate with digital back end.What's more,with the rapid development of silicon-based technology,the frequency of transistors under advanced silicon-based technology is constantly improving,and it can satisfy the most requirements of RF/mmWave integrated circuit design.Under these conditions,it's a great choice to implement transceivers by silicon-based technology.As the operating frequency of the transceiver systems is continuously improved,plenty of passive devices such as on-chip inductors and on-chip transformers have been widely used in RF/mmWave integrated circuits to implement many functions such as matching and conversion between differential and single ended.However,the equivalent circuit models of inductors provided by foundries are only 20 GHz below,the models of transformers are usually not provided,and accuracy of simulation models at high frequency also decreased.What's more,structures of passive devices provided by foundries are limited,circuit designers often need to design new structures to meet pratical requirements.Therefore,modeling of passive devices plays a key role in the design of RF/mmWave integrated circuits.This thesis mainly studies the modeling of silicon-based millimeter-wave passive devices and the methods of parameter extraction.Finally,modeling technology is applied to the design of downconversion mixer which is working in millimeter wave.The contents of this thesis are as follows:(1).Based on the analysis of the energy loss mechanism of passive devices on silicon substrates,single ? equivalent circuit models and methods of model parameter extraction for on-chip inductors are proposed for RF and millimeter wave band.To overcome the drawbacks of single ? model,double ? model is also proposed.Through the tapeout,multiple test structures are measured.Acording to the comparison betweenmodel simulation results and measured results,the accuracy of the model is verified from DC to 35 GHz.(2).Based on the research on the modeling technology of inductors,on-chip transformers are researched.And the corresponding models and parameter extraction methods are built.To verify accuracy of the model,different test structures of transformer are measured,and model calculation results have a great agreement with measured results from DC to 35 GHz.(3).After research of the modeling technology of on-chip passive devices,based on CMOS 65 nm process,a downconversion mixer which is applied at 5G communication system is designed.Passive devices like positive feedback transformer and balun are designed in the mixer.After tapeout,some specifications such as conversion gain,1dB compression point are tested.According to measurement results,at the frequency range from 37.5GHz to 40.5GHz,the mixer consumes power of 21 mW,and achieves1.8dB maximum gain(loss of baluns of every port included),-3dBm input 1dB compression point.And simulated minimum noise figure of the mixer is 10.9dB.Measurement results are consistent with the simulation results.