Parameter Extraction And Software Design Of Large-signal Model Of Heterojunction Bipolar Transistor

With the rapid development of integrated circuits in the fields of microwave and terahertz,heterojunction bipolar transistor(HBT)has attracted wide attention from researchers with its advantages of high gain,high frequency,and high reliability.As one of the high frequency electronic devices,HBT devices have broad application prospects.However,the device models still need to be improved.Model parameters are one of the important parts of the device model,and the extraction of precise parameters is of great significance.This dissertation studied the model parameter extraction and software design of HBT devices.By analyzing the principle of the large-signal equivalent circuit model and parameter extraction method for HBT devices,a method based on direct parameter extraction and algorithm optimization is proposed.Based on the symbolically-defined device(SDD)technology,a VBIC equivalent large-signal circuit model is established.Combining the parameter extraction method in this dissertation with SDD model,a parameter extraction software is designed.The main work of this dissertation is as follows:(1)After analyzing the characteristics of the large-signal equivalent circuit models for commonly used HBT devices,the VBIC model and the Agilent model applicable to the III-V family are compared.The structure of VBIC equivalent circuit model is studied,and the simplified VBIC model is obtained by ignoring the components that have weak influence on the whole device.The SDD model based on simplified VBIC model is established by using SDD technology.The simulation results are in good agreement with SPICE model.(2)The method of model parameter extraction is analyzed.The basic principle of differential evolution method and its deficiency in parameter optimization are studied.The corresponding improvement strategy and parameter optimization flow are proposed.(3)Based on the proposed parameter extraction method and SDD model,a parameter extraction software was developed,which can extract parameters quickly and accurately.In this dissertation,the dc parameters of three models with different device sizes are extracted by this software.Then the SDD model with these parameters is simulated.The simulation values are compared with the measured values,which are in good agreement.Finally,the extraction of AC parameters is verified by literature data,and the relative error is small compared with the reference value of literature.