A Scalable Model of the Substrate Network in Deep n-Well RF MOSFETs with Multiple Fingers

A novel scalable model of substrate components for deep n-well (DNW) RF MOSFETs with different number of fingers is presented for the first time. The test structure developed in [1] is employed to directly access the characteristics of the substrate to extract the different substrate components. A methodology is developed to directly extract the parameters for the substrate network from the measured data. By using the measured two-port data of a set of nMOSFETs with different number of fingers, with the DNW in grounded and float configuration, respectively, the parameters of the scalable substrate model are obtained. The method and the substrate model are further verified and validated by matching the measured and simulated output admittances. Excellent agreement up to 40 GHz for configurations in common-source has been achieved.

基于PSO⁃BP神经网络的可缩放微波晶体管非线性电流建模

提出了一种基于人工神经网络的InP异质结双极晶体管(Heterojunction bipolar transistor,HBT)可缩放非线性电流模型,准确地表征了不同尺寸、不同温度下的直流特性。该模型采用了具有良好泛化能力的反向传播(Back⁃propagation,BP)神经网络,并使用粒子群优化(Particle swarm algorithm,PSO)算法找到最佳的网络权重和偏置来规避其容易陷入局部最小值的问题。对不同尺寸、不同温度和不同偏置下的器件非线性直流特性测试数据,将其分为训练数据集和测试数据集,基于PSO⁃BP神经网络进行训练。最终,通过对比收敛迭代次数、不同温度下的可缩放非线性电流精度以及建模结果,验证了PSO⁃BP神经网络能够很好地表征InP HBT器件在不同温度下的可缩放非线性电流特性,证实了该模型具有较快的收敛速度、建模精度和泛化能力。

On large-signal modeling of GaN HEMTs: past, development and future

In the past few decades,circuits based on gallium nitride high elec-tron mobility transistor(GaN HEMT)have demonstrated exceptional potential in a wide range of high-power and high-frequency applica-tions,such as the new generation mobile communications,object de-tection and consumer electronics,etc.As a critical intermediary be-tween GaN HEMT devices and circuit-level applications,GaN HEMT large-signal models play a pivotal role in the design,application and development of GaN HEMT devices and circuits.This review pro-vides an in-depth examination of the advancements in GaN HEMT large-signal modeling in recent decades.Detailed and comprehensive coverage of various aspects of GaN HEMT large-signal model was of-fered,including large-signal measurement setups,classical formula-tion methods,model classification and non-ideal effects,etc.In order to better serve follow-up researches,this review also explored poten-tial future directions for the development of GaN HEMT large-signal modeling.

Physical modeling based on hydrodynamic simulation for the design of InGaAs/InP double heterojunction bipolar transistors

A physical model for scaling and optimizing InGaAs/InP double heterojunction bipolar transistors（DHBTs） based on hydrodynamic simulation is developed.The model is based on the hydrodynamic equation,which can accurately describe non-equilibrium conditions such as quasi-ballistic transport in the thin base and the velocity overshoot effect in the depleted collector.In addition,the model accounts for several physical effects such as bandgap narrowing,variable effective mass,and doping-dependent mobility at high fields.Good agreement between the measured and simulated values of cutoff frequency,f t,and maximum oscillation frequency,f max,are achieved for lateral and vertical device scalings.It is shown that the model in this paper is appropriate for downscaling and designing InGaAs/InP DHBTs.

高功率GaN微波器件大信号缩放模型

基于经验基EEHEMT等效电路模型,针对AlGaN/GaN HEMTs提出一种可缩放大信号模型,以准确获取宽栅多指器件的电学性能.所提出的模型从器件的栅宽、栅指个数角度出发,分别对器件模型的本征参数漏源电流、栅源电容和栅漏电容制定了相应的缩放规则.为了验证所提缩放大信号模型的准确性,通过总栅宽为14.4 mm的L频段GaN高效率功率放大器进行比对验证,仿真与测试结果在1120—1340 MHz频带内功率值不低于46.5 dBm,漏极效率值不低于70%,结果高度吻合.此外,利用该模型在对大栅宽GaN HEMTs基波信息进行准确仿真的基础上能很好预测器件的高次谐波信息,可为先进大功率、高效率的微波功率放大器的设计提供重要支撑.

脱贫农户返贫风险评估及防范机制构建的实证分析

识别脱贫农户返贫风险并制定有效的治理策略是现阶段解决脱贫攻坚和乡村振兴有效衔接的关键所在,也是实现农民共同富裕的重要任务。针对脱贫农户生活水平不稳定可能导致的返贫问题,基于陕南脱贫农户的实地调查数据,构建返贫风险指标评价体系并利用物元模型评估脱贫农户返贫风险程度,深层次剖析返贫风险的影响因素,建立脱贫农户返贫防范机制。研究认为:陕南大部分脱贫农户处于一般风险水平,且差异较小;脱贫农户成员健康状况、遭遇自然灾害风险、环境污染影响农产品质量风险和社会关系网是导致陕南脱贫农户可能返贫的重要因素,说明脱贫区的政策制度、自然环境和资源禀赋、脱贫农户个体能力是陕南脱贫农户可能返贫的影响因素;建立依据事前防御、事中处理、事后追踪体系的全过程性风险预警机制,加强脱贫农户思想观念培育,注重内生动力提升,提高脱贫农户对外部环境变化的适应能力,打造能够产生经济效益的优势产业,促进生态农业、农旅产业、文化产业发展,改善升级乡村教育医疗,提高道路水利、信息网络、天然气能源等基础设施建设,促进脱贫农户社会资本积累,提高可持续生计水平和社会参与能力。

MOS Model 20 Based RF-SOI LDMOS Large-Signal Modeling

A novel large-signal equivalent circuit model of RF-SOI LDMOS based on Philips MOS Model 20 （MM20） is presented. The weak avalanche effect and the power dissipation caused by self-heating are described. The RF parasitic elements are extracted directly from measured S-parameters with analytical methods. Their final values can be obtained quickly and accurately through the necessary optimization. The model is validated in DC,AC small-signal,and large-signal analyses for an RF-SOI LDMOS of 20-fingers （channel mask length, L = 1μm,finger width, W = 50μm） gate with high resistivity substrate and body-contact. Excellent agreement is achieved between simulated and measured results for DC, S- parameters （10MHz-0.01GHz）, and power characteristics, which shows our model is accurate and reliable. MM20 is improved for RF-SOI LDMOS large-signal applications. This model has been implemented in Verilog-A using the ADS circuit simulator （hpeesofsim）.

Scalable modeling and comparison for spiral inductors using enhanced 1-π and 2-π topologies

Two different scalable models developed based on enhanced 1-πand 2-πtopologies are presented for onchip spiral inductor modeling.All elements used in the two topologies for accurately predicting the characteristics of spiral inductors at radio frequencies are constructed in geometry-dependent equations for scalable modeling.Then a comparison between the 1-πand 2-πscalable models is made from the following aspects：the complexity of equivalent circuit models and parameter-extraction procedures,scalable rules and the accuracy of scalable models.The two scalable models are further verified by the excellent match between the measured and simulated results on extracted parameters up to self-resonant frequency（SRF） for a set of spiral inductors with different L,R and N,which are fabricated by employing 0.18-μm 1P6M RF CMOS technology.

船舶与海洋大数据算法模型资源共享系统

为了解决船舶与海洋大数据算法模型资源共享问题,本文构建船舶与海洋大数据算法模型资源共享系统,系统具备研制、优化、集成船舶行业和海洋领域专用算法模型资源能力,以源代码或二进制库方式对船舶行业和海洋领域专用算法模型资源进行集成,通过RestfulAPI接口方式为外部授权应用系统提供模型算法计算服务。性能测试结果表明,船舶与海洋大数据算法模型资源共享系统具备多用户并发算法模型资源共享服务能力和性能可扩展性。

A symbolically defined InP double heterojunction bipolar transistor large-signal model

A self-built accurate and flexible large-signal model based on an analysis of the characteristics of InP double heterojunction bipolar transistors （DHBTs） is implemented as a seven-port symbolically defined device （SDD） in Agilent ADS. The model accounts for most physical phenomena incluuing the self-heating effect, Kirk effect, soft knee effect, base collector capacitance and collector transit time. The validity and the accuracy of the large-signal model are assessed by comparing the simulation with the measurement of DC, multi-bias small signal S parameters for InP DHBTs.

Scalable wideband equivalent circuit model for silicon-based on-chip transmission lines

A scalable wideband equivalent circuit model of silicon-based on-chip transmission lines is presented in this paper along with an efficient analytical parameter extraction method based on improved characteristic function approach,including a relevant equation to reduce the deviation caused by approximation.The model consists of both series and shunt lumped elements and accounts for high-order parasitic effects.The equivalent circuit model is derived and verified to recover the frequency-dependent parameters at a range from direct current to 50 GHz accurately.The scalability of the model is proved by comparing simulated and measured scattering parameters with the method of cascade,attaining excellent results based on samples made from CMOS 0.13 and 0.18 μm process.

Large-signal SPICE model for depletion-type silicon ring modulators

We present an accurate, easy-to-use large-signal SPICE circuit model for depletion-type silicon ring modulators(Si RMs). Our model includes both the electrical and optical characteristics of the Si RM and consists of circuit elements whose values change depending on modulation voltages. The accuracy of our model is confirmed by comparing the SPICE simulation results of 25 Gb/s non-return-to-zero(NRZ) modulation with the measurement. The model is used for performance optimization of monolithically integrated Si photonic NRZ and pulse-amplitudemodulation 4 transmitters in the standard SPICE circuit design environment.

基于转移阻抗模型的功率回路和信号回路间串扰建模与试验验证

由于列车和船舶上的空间有限,互连非屏蔽线缆的空间非常小,导致非屏蔽线缆之间存在严重的串扰问题,其中功率回路对信号回路的串扰会严重影响信号的质量和系统的正常运行,因此有必要估计功率回路中共模和差模电磁干扰对信号回路的影响。为此提出了一种可扩展的级联多端口网络模型,可对线缆间共模和差模串扰进行精准建模,准确估计出功率回路对信号回路的影响。最后,搭建了试验台架进行验证,实验结果验证了该方法的有效性。

存在测量误差的高斯图模型估计

众所周知,如果将损坏的数据直接应用于为干净数据设计的回归方法中,将导致错误的结果。尽管最近高斯图模型估计在方法以及算法上都取得了不错的进展,但如何在受污染的协变量下实现高效和可扩展的高斯图模型估计尚不清楚。本文针对加性和乘性测量误差下的高斯图模型开发了一种称为凸条件创新可扩展有效估计(COCOISEE)的新方法。该方法结合了高斯图模型中创新的可扩展高效估计和最近半正定矩阵投影的优点,从而在估计过程中具有逐步凸性和可扩展性。我们为该方法提供了全面的理论保证,并且通过数值研究证明了所提出方法的有效性。

基于分布式模型预测控制的车辆队列拓展策略

为提高自动化联网车辆队列的灵活性和拓展性,提出一种基于分布式模型预测控制的车辆队列拓展策略。以四元素车辆队列模型为框架,结合二维非线性运动学的节点动力学模型,利用信息流拓扑结构下车辆间邻域信息和分阶段控制策略,将车辆队列拓展过程描述成3类典型优化问题的组合,结合行车安全性及舒适性要求,分别设计分布式预测控制器,并采用仿真实例进行验证。研究结果表明,所提出的拓展策略能够实时优化相邻车道车辆融入主车道队列的动态过程。

RF CMOS modeling:a scalable model of RF-MOSFET with different numbers of fingers

A novel scalable model for multi-finger RF MOSFETs modeling is presented.All the parasitic components, including gate resistance,substrate resistance and wiring capacitance,are directly determined from the layout.This model is further verified using a standard 0.13μm RF CMOS process with nMOSFETs of different numbers of gate fingers,with the per gate width fixed at 2.5μm and the gate length at 0.13μm.Excellent agreement between measured and simulated S-parameters from 100 MHz to 20 GHz demonstrate the validity of this model.

A millimeter wave large-signal model of GaAs planar Schottky varactor diodes

A millimeter wave large-signal model of GaAs planar Schottky varactor diodes based on a physical analysis is presented.The model consists of nonlinear resistances and capacitances of the junction region and external parasitic parameters.By analyzing the characteristics of the diode under reverse and forward bias,an extraction procedure of all of the parameters is addressed.To validate the newly proposed model,the PSVDs were fabricated based on a planar process and were measured using an automatic network analyzer.Measurement shows that the model exactly represents the behavior of GaAs PSVDs under a wide bias condition from -10 to 0.6 V and for frequencies up to 40 GHz.

MEXTRAM model based SiGe HBT large-signal modeling

An improved large-signal equivalent-circuit model for SiGe HBTs based on the MEXTRAM model （level 504.5） is proposed. The proposed model takes into account the soft knee effect. The model keeps the main features of the MEXTRAM model even though some simplifications have been made in the equivalent circuit topology. This model is validated in DC and AC analyses for SiGe HBTs fabricated with 0.35-μm BiCMOS technology, 1 × 8 μm^2 emitter area. Good agreement is achieved between the measured and modeled results for DC and S-parameters （from 50 MHz to 20 GHz）, which shows that the proposed model is accurate and reliable. The model has been implemented in Verilog-A using the ADS circuit simulator.

RF CMOS modeling:a novel empirical large-signal model for an RF-MOSFET

A novel empirical model for large-signal modeling of an RF-MOSFET is proposed. The proposed model is validated in the DC, AC, small-signal and large-signal characteristics of a 32-finger nMOSFET fabricated in SMIC＇s 0.18 μm RF CMOS technology. The power dissipation caused by self-heating is described. Excellent agreement is achieved between simulation and measurement for DC, S-parameters （50 MHz-40 GHz）, and power characteristics, which shows that our model is accurate and reliable.

A complete and accurate surface-potential based large-signal model for compound semiconductor HEMTs

A complete and accurate surface potential based large-signal model for compound semiconductor HEMTs is presented. A surface potential equation resembling the one used in conventional MOSFET models is achieved. The analytic solutions from the traditional surface potential theory that developed in MOSFET models are inherited. For core model derivation, a novel method is used to realize a direct application of the standard surfacepotentialmodelofMOSFETsforHEMTmodeling,withoutbreakingthemathematicstructure.Thehigh-order derivatives of I–V /C–V remain continuous, making the model suitable for RF large-signal applications. Furthermore, the self-heating effects and the transconductance dispersion are also modelled. The model has been verified through comparison with measured DC IV, Gummel symmetry test, CV, minimum noise figure, small-signal Sparameters up to 66 GHz and single-tone input power sweep at 29 GHz for a 475 m0.1 m InGaAs/GaAs power pHEMT, fabricated at a commercial foundry.