SiGe HBT非准静态小信号等效电路的参数提取

提出了一种硅锗异质结双极型晶体管（SiGe HBT）非准静态效应的小信号等效电路模型的参数提取方法。整个参数提取过程建立在由非准态效应的小信号等效电路推导出的一系列泰勒级数解析公式并结合参数直接法,该方法依赖于测量的S参数,不使用任何的数值优化法,参数提取结果使用CAD仿真验证。结果表明该参数提取方法简单易行,较为精确,该方法能够用到不同工艺SiGe HBT参数提取。     

AlGaN/GaN HEMT器件小信号等效电路参数值的提取

利用国际通用的ColdFET以及宽带小信号提取方法对AlGaN/GaN HEMT器件进行小信号参数的提取,用仿真软件ADS(advanced design system)建立HEMT小信号等效电路模型,并对参数值进行优化.可快速提取器件的小信号参数并给予工艺一些反馈和指导.     

AlGaN/GaN HEMT器件小信号等效电路参数值的提取

利用国际通用的ColdFET以及宽带小信号提取方法对AlGaN/GaN HEMT器件进行小信号参数的提取,用仿真软件ADS(advanced design system)建立HEMT小信号等效电路模型,并对参数值进行优化.可快速提取器件的小信号参数并给予工艺一些反馈和指导.     

应用遗传算法提取GaAs场效应管小信号模型参数

利用阻抗矩阵法求出GaAs场效应管的小信号等效电路S参数,并提出应用遗传算法提取等效电路模型参数.该法具有收敛快速、精确度高的特点,使各个模型参数均能得到较为精确快速的提取.     

用模拟退火算法从S参数提取HFET小信号等效电路模型参数

微波集成电路和微波器件的设计需要准确地提取 HFET的小信号等效电路模型参数 .采用带回火的模拟退火算法从 S参数提取 HFET小信号等效电路模型参数 ,得到了高质量的解 .计算结果是全局最优解 ,摆脱了初始值的影响 ,并且克服了局部优化算法遇到的不收敛或收敛到错误解的问题 .利用测量得到的栅电阻 ,计算结果的精度可以进一步提高 .这个算法同样也适用于 HBT、电容和电感等器件模型参数的提取     

一种改进的InP HBT小信号模型的直接提取法

提出了一种改进的直接提取方法来提取InP HBT小信号等效电路中的模型参数,并将其成功地应用InP异质结双极晶体管（HBT）小信号等效电路。在所采用的模型中考虑了分布式基极-集电极电容效应。与其他直接参数提取方法相比,该方法从外围寄生元件到内部本征元件依次进行参数提取,提取过程较为清晰。除寄生参数外,其余所有的参数计算均未经过任何简化近似。该方法依赖于S参数的测量,所有等效电路参数直接从S参数数据中提取,而无需任何基于初始值的近似。在0.1 ~ 40 GHz的频率范围内,直接提取法在InP HBT上得到了成功的验证,并在整个频率范围内得到了较好的测量结果与计算结果的一致性。     

基于物理结构的GaN HEMTs小信号等效电路的精确建模方法研究

为了有效地表征GaN HEMTs在微波频段下的电学特性,研究了其高频等效电路的精确建模方法。基于GaN HEMTs器件的本征物理结构,综合考虑器件在制版过程中由电极和通孔所带来的寄生特性,描述了一种具有26个详细参数网络的小信号等效电路模型。此模型考虑了器件在工作环境下所受到的集肤效应,同时通过对小信号等效电路进行双端口网络参数分析,推导了其准静态近似的微波等效电路参数直接提取的简化算法,最终通过ADS仿真平台将所建模型和传统模型的S参数模拟结果与实测数据的一致性进行对比,验证了小信号等效电路模型的精确性与参数提取算法的有效性。     

一种改进的InP HBT小信号模型的直接提取法（英文）

提出了一种改进的直接提取方法来提取InP HBT小信号等效电路中的模型参数,并将其成功地应用InP异质结双极晶体管(HBT)小信号等效电路。在所采用的模型中考虑了分布式基极-集电极电容效应。与其他直接参数提取方法相比,该方法从外围寄生元件到内部本征元件依次进行参数提取,提取过程较为清晰。除寄生参数外,其余所有的参数计算均未经过任何简化近似。该方法依赖于S参数的测量,所有等效电路参数直接从S参数数据中提取,而无需任何基于初始值的近似。在0.1～40 GHz的频率范围内,直接提取法在InP HBT上得到了成功的验证,并在整个频率范围内得到了较好的测量结果与计算结果的一致性。     

AlGaN/GaN高电子迁移率晶体管小信号等效电路的参数提取

本文在高电子迁移率晶体管(HEMT)小信号等效电路模型的基础上,考虑了AlGaN/GaN HEMT的结构特性,具体分析了寄生参数和本征参数的提取方法.采用这些方法,实际测量了5～10 GHz频率下HEMT器件的小信号S参数并提取了它的电学参数,S参数的计算值与实际测量值进行了比较.实验结果表明此方法简单易行,较为精确.     

微波功率SiC MESFET小信号等效电路建模研究

在传统GaAs MESFET器件小信号模型基础上提出一种更适合SiC MESFET器件的小信号等效电路模型.该模型在引入了与栅压相关的输入电导后,明显改善了S11的拟合精度.提出直接利用cold FET反向栅压偏置下的S参数,通过曲线拟合和外插技术提取SiC MESFET小信号等效电路寄生参数的方法.该模型应用于国内SiCMESFET工艺线,在O.5～18GHz范围内S参数的仿真值和实测值非常吻合.     

A New Millimeter-Wave Small-Signal Modeling Approach for pHEMTs Accounting for the Output Conductance Time Delay

A new technique is developed for determining analytically a millimeter-wave small-signal equivalent-circuit model of GaAs pseudomorphic HEMTs from scattering parameter measurements. In order to obtain a good agreement between model simulations and measurements up to 90 GHz, the conventional intrinsic output conductance is substituted by a voltage-controlled current source with a time delay. Consequently, a simple and accurate extraction procedure is proposed for taking into account the introduction of the output conductance time delay.     

A new pinched-off cold-FET method to determine parasiticcapacitances of FET equivalent circuits

A new pinched-off cold FET method to extract the parasitic capacitances of FETs is proposed in this paper. The method is based on a physically meaningful depletion-layer model and the theoretical analysis of the two-port network for the pinched-off cold FETs. The parasitic gate capacitance (C_pg) and the parasitic drain capacitance (C _pd) of FETs are extracted using the linear regression technique associated with the frequency responses of Y-parameters. The extraction method can be applied to the small-signal equivalent-circuit modeling of the FETs including MESFETs, heterojunction FETs, and high-electron-mobility transistors. According to the new analytical method, the simulated S-parameters exhibit great agreement with the measured S-parameters for the equivalent-circuit models of FETs     

An Improved Small-Signal Parameter-Extraction Algorithm for GaN HEMT Devices

A highly efficient and accurate extraction algorithm for the small-signal equivalent-circuit parameters of a GaN high electron-mobility transistor device is presented. Elements of the extrinsic equivalent-circuit topology are evaluated using a modified “cold field-effect transistor” approach whereby the undesirable need to forward bias the device's gate terminal is avoided. Intrinsic elements are determined based on a circuit topology, which identifies, for the first time, a time delay in the output conductance of GaN-based devices. The validity of the proposed algorithm has been thoroughly verified with excellent correlation between the measured and modeled $S$-parameters up to 50 GHz.      

Direct parameter-extraction method for HBT small-signal model

An accurate and broadband method for the direct extraction of heterojunction bipolar transistor (HBT) small-signal model parameters is presented in this paper. This method differs from previous ones by extracting the equivalent-circuit parameters without using special test structures or global numerical optimization techniques. The main advantage of this method is that a unique and physically meaningful set of intrinsic parameters is extracted from the measured S-parameters for the whole frequency range of operation. The extraction procedure uses a set of closed-form expressions derived without any approximation. An equivalent circuit for the HBT under a forward-bias condition is proposed for extraction of access resistances and parasitic inductances. An experimental validation on a GaInP/GaAs HBT device with a 2×25 μm emitter was carried out, and excellent results were obtained up to 30 GHz. The calculated data-fitting residual error for three different bias points over 1-30 GHz was less then 2%     

A pure analytic method for direct extraction of collector-up HBT's small-signal parameters

A pure analytic procedure for direct extraction of the small-signal equivalent-circuit parameters, including extrinsic inductances, has been demonstrated and successfully applied to III-V and SiGe collector-up heterojunction bipolar transistors (HBTs). This method can alleviate some difficulties encountered among conventional extracting techniques that are the use of additional test structures, forward-biased measurements at specific bias conditions, and empirical optimization process. In this paper, the hybrid-/spl pi/ equivalent-circuit elements are extracted in a simple and efficient way from impedance and admittance formulation on the basis of measured S-parameters. To study the bias dependence, the extrinsic and intrinsic circuit components are evaluated under different bias conditions. The model parameters are sequentially derived during the extraction process yielding a full set of physical element values. The validity of our model is explored on pnp collector-up AlGaAs-InGaAs HBTs, and a good coincidence between measured and modeled S-parameters is observed for the entire frequency range of operation. Consistent extracted trends indicate that this improved equivalent-circuit model is suitable to be implemented in circuit simulators for microwave-circuit TCAD applications.     

On the accuracy of direct extraction of the heterojunction-bipolar-transistor equivalent-circuit model parameters C/sub /spl pi//, C/sub BC/, and R/sub E/

Several basic small-signal equivalent-circuit models for bipolar transistors lead to simple analytical expressions for the model parameters in terms of measured values. This paper investigates the accuracy of these expressions for real transistors by applying the direct extraction equations to more complicated small-signal models. The extraction of the base/collector capacitance, base/emitter capacitance, and emitter resistance are considered. Analytically derived trends are illustrated using measurements on small-area high-speed InP/GaAsSb/InP double heterojunction bipolar transistors.     

A new small-signal modeling approach applied to GaN devices

A new small-signal modeling approach applied to GaN-based devices is presented. In this approach, a new method for extracting the parasitic elements of the GaN device is developed. This method is based on two steps, which are: 1) using cold S-parameter measurements, high-quality starting values for the extrinsic parameters that would place the extraction close to the global minimum of the objective function for the distributed equivalent circuit model are generated and 2) the optimal model parameter values are searched through optimization using the starting values already obtained. The bias-dependent intrinsic parameter extraction procedure is improved for optimal extraction. The validity of the developed modeling approach and the proposed small-signal model is verified by comparing the simulated wide-band small-signal S-parameter, over a wide bias range, with measured data of a 0.5-/spl mu/m GaN high electron-mobility transistor with a 2/spl times/50 /spl mu/m gatewidth.     

Efficient numerical solution of the transmission-line equivalent-circuit model of a semiconductor

A numerical algorithm is described that allows the transmission-line equivalent-circuit model of a semiconductor to be solved very efficiently. The technique is shown to be about three times as efficient as the `transmission-matrix? approach for computing the small-signal a.c. properties of semiconductor devices from the equivalent-circuit model.     

DC to high-frequency HBT-model parameter evaluation using impedanceblock conditioned optimization

A new heterojunction bipolar transistor (HBT) small-signal equivalent-circuit parameter-extraction procedure employing multibias S-parameter data is presented. The algorithm combines analytical and empirical parameter evaluation techniques and results in a bias-dependent HBT model. To minimize the risk of nonphysical parameter estimation, elements such as the DC transport factor, α_o, and the emitter-base conductance are evaluated from the device DC characteristics, and the frequency dispersion of α is related to the RC time-constant of the emitter-base junction. Moreover, initial values for the extrinsic device parasitics are obtained from “hot” as well as “cold” S-parameter data. The method results in excellent fit between measured and modeled S-parameter data in the frequency range DC-40 GHz and for a wide range of bias operating points