On the use of behavioral modeling within the RFIC design flow: Satellite receiver case study

In order to generate a first-time right design, system level modeling and simulation is a major step. Thus, performance evaluation of integrated wireless systems requires the development of RF behavioral models compatible with the microelectronic design tools. Firstly, this paper shows the need of such models within the RFIC Top–Down design flow. Then, behavioral modeling techniques are presented and several classical RF block models are described. Those models are used within an RFIC satellite receiver validation example and finally, several performance evaluation examples allow demonstrating the capabilities of behavioral modeling, compared to other very used modeling techniques as mathematical and baseband approaches.     

基于FLAMES的电子战仿真模型的组合建模

随着军用仿真技术的不断发展,使得多领域的模型集成变得更加困难,模型组合和可重用性不足问题显得十分突出。阐述了组合建模和柔性行为分析与建模评估系统（FLAMES）建模原理,针对FLAMES柔性仿真框架下建模灵活性的特点,并结合关联假设的组合建模理论,提出了基于FLAMES的电子战仿真模型的组合仿真概念框架和建模方法,以某型电子战飞机为例,通过仿真实验分析仿真数据。结果表明,该方法能够有效对模型进行组合建模,能为基于FLAMES柔性仿真框架的模型组件开发及其组合建模提供一定的依据。     

Practical modeling for circuit simulation

There is much more to modeling for circuit simulation than deriving a set of I(V), and perhaps Q(V), equations and extracting a SPICE MODEL card. Unfortunately, some practical aspects of modeling are often overlooked. This paper details common-sense guidelines for modeling and highlights common modeling problems. Particular emphasis is given on understanding accuracy requirements and numerical requirements, on ensuring that compact models are asymptotically correct, and on highlighting the real goal of modeling for circuit simulation: getting complete models for allowable device layouts working in the CAD system on a designer's desk     

IC Immunity Modeling Process Validation Using On-Chip Measurements

Developing integrated circuit (IC) immunity models and simulation flow has become one of the major concerns of ICs suppliers to predict whether a chip will pass susceptibility tests before fabrication and avoid redesign cost. This paper presents an IC immunity modeling process including the standard immunity test applied to a dedicated test chip. An on-chip voltage sensor is used to characterize the radio frequency interference propagation inside the chip and thus validate the immunity modeling process.     

Statistical device models from worst case files and electrical testdata

Two statistical metal oxide semiconductors (MOS) models are described, one based on worst case files and the other on electrical test data. The former is appropriate for predicting the variability of a process early in its life cycle, while the latter would better track a maturing process. The key statistical tool that is used to develop the models is principal component analysis (PCA), which is used in novel ways in order to derive statistical models from readily available information. The models are used to perform statistical circuit simulation in order to quantitatively predict the impact of manufacturing variations on circuit performance metrics. Due to the use of linear response surface modeling and latin hypercube sampling, the simulation cost of using the models is about the same as with worst case simulation. The modeling technique is general and is applicable to other semiconductor devices besides MOS devices which are considered in this paper     

Model requirements for simulation of low-voltage MOSFET in automotive applications

This paper focuses on the modeling of low-voltage automotive power electronic circuits to obtain accurate system simulation, including estimation of losses. The aim is to compare several metal-oxide semiconductor field-effect transistor (MOSFET) models to find out which can be used for low-voltage, high-current automotive converter simulations. As these models are intended for system simulation, only analytical models are addressed as they may be implemented into any circuit simulator. The different modes of operation of the switches are described (commutation, synchronous rectification, avalanche...), and several models of the power MOSFET transistor, allowing for simulation in these modes, are presented. Special care is given to the parameter extraction methods and to the interconnection model of the commutation cell. The four test circuits used to identify the low-voltage power MOSFET model parameters are presented. Comparison between simulations and measurements obtained with a calorimeter are then detailed. This measurement method is accurate and offers a simple way to prove the quality of simulation results. It is shown that the parameter identification is of major concern to achieve high accuracy, as classical Spice models can give good results, providing the model parameters are correctly set.     

IC process modeling and topography design

The device features in the third dimension in VLSI affect packing density and circuit performance. Establishing techniques to characterize and design these nonplanar device features is a major goal of the research on IC process modeling and simulation. Simulation is well accepted as a means of optimizing individual lithography, etching, and deposition processes. It is also well suited for studying the complex tradeoffs between conflicting physical mechanisms in the context of complete multistep process sequences. The success of modeling and simulation has created a demand for more extensive models and new applications. IC process modeling and simulation will not only contribute heavily to technology design but also offers a potential window through the layout role bottleneck for more complete design insight and optimization.     

Modeling and simulation of VLSI digital systems

Discrete simulation of digital circuits is a vital tool in the design process. However, few people are aware of the modeling assumptions inherent in discrete simulation. Nor is there a widely accepted and consistent theory of modeling and simulation of discrete/digital systems. In this paper we concentrate on the basic ideas behind discrete modeling and present a discussion of the most popular algorithms used in writing simulators. In addition, we use the characteristics of discrete models to define the logic, functional, and behavioral levels of simulation. In closing, we discuss new issues in modeling and simulation.     

Finite element modeling in surgery simulation

Modeling the deformation of human organs for surgery simulation systems has turned out to be quite a challenge. Not only is very little known about the physical properties of general human tissue but in addition, most conventional modeling techniques are not applicable because of the timing requirements of simulation systems. To produce a video-like visualization of a deforming organ, the deformation must be determined at rates of 10-20 times/s. In the fields of elasticity and related modeling paradigms, the main interest has been the development of accurate mathematical models. The speed of these models has been a secondary interest. But for surgery simulation systems, the priorities are reversed. The main interest is the speed and robustness of the models, and accuracy is of less concern. Recent years have seen the development of different practical modeling techniques that take into account the reversed priorities and can be used in practice for real-time modeling of deformable organs. The paper discusses some of these new techniques in the reference frame of finite element models. In particular, it builds on the recent work by the author on fast finite element models and discusses the advantages and disadvantages of these models in comparison to previous models     

Behavioral modeling phase-locked loops for mixed-mode simulation

Phase-locked Loops(PLLs) are a class of feedback systems with wide range of applications. A PLL in its entirety can be viewed as a closed-loop servosystem, comprised of three major functional subsystems; 1) Phase detectors, 2) Loop filters and 3) Voltage/Current controlled oscillators. The overall characteristics of the phase-locked loop are dependent on the realization of individual subsystems which have mixed analog-digital implementations. In simulating a PLL, one has to deal with the mixed-signal nature of most implementations, as well as the problem of simulating the PLL over a large number of signal cycles. Long simulation run times plague the simulation of a PLL using a conventional simulator, sometimes making such simulation impractical. In the methodology described in this paper, these drawbacks are overcome by the use of behavioral models and a mixed-signal simulation platform. This paper presents a general mixed-mode behavioral simulation methodology and the derivation of behavioral simulation models for various kinds of PLLs. The top-down and bottom-up modeling paradigms are illustrated through the use of examples of actual PLL designs. The simulation models are generated for the AT&T Bell Laboratories mixed analog-digital simulator, ATTSIM.     

多晶硅TFT模型的研究进展

全面介绍了多晶硅薄膜晶体管(TFT)紧凑模型的现状和应用前景,简单说明了多晶硅TFT特有的电学特性,这是多晶硅TFT建模的基础,重点介绍了基于阈值电压和基于表面势的多晶硅TFT紧凑模型的研究进展,并对这些模型进行了评述,其中RPI模型是基于阈值电压的TFT模型的典范.虽然TFT模型已经有所发展,但成熟度还远远不够.最后提出了改进多晶硅TFT模型的方向和策略,包括二维器件模拟的应用、基于表面势模型的发展、多晶硅材料特性的应用、统一模型的发展、短沟效应的建模和参数提取等.     

System of Systems Approach to Formal Modeling of CPS for Simulation‐Based Analysis

This paper presents a system‐of‐systems (SoS) approach to the formal modeling of a cyber‐physical system (CPS) for simulation‐based analysis. The approach is based on a convergence technology for modeling and simulation of a highly complex system in which SoS modeling methodology, hybrid systems modeling theory, and simulation interoperation technology are merged. The methodology maps each constituent system of a CPS to a disparate model of either continuous or discrete types. The theory employs two formalisms for modeling of the two model types with formal specification of interfaces between them. Finally, the technology adapts a simulation bus called DEVS BUS whose protocol synchronizes time and exchange messages between subsystems simulation. Benefits of the approach include reusability of simulation models and environments, and simulation‐based analysis of subsystems of a CPS in an inter‐relational manner.     

基于模型驱动设计方法的雷达仿真系统实现

根据某装备中雷达仿真系统的特点和需求,采用基于模型驱动的设计方法,在Rhapsody中应用UML2.0标准建模语言建立了系统开发过程中各个阶段的模型,根据模型设计并实现了雷达仿真系统。通过系统模型化的设计,使系统开发的重点从编码转到了建模之上,从而使系统的开发变得直观,且提高了系统的可靠性。     

CDMA网络规划的线性建模方法

该文提出了CDMA网络规划的线性建模方法。该方法用线性方程组对 CDMA系统进行建模,并可用迭代的方法求解,该文同时给出了模型的仿真结果,仿真结果表明,该方法具有较高的准确性,完全可以用于对实际网络的规划,同时,该方法便于用计算机实现,可以作为规划软件的算法模型。     

基于Creator的视景仿真建模技术

根据三维视景仿真场景实时性要求高的特点，对三维模型的建模及优化提出了更高要求。综合利用Multigen Creator和Terra Vista等软件，以“MQ-1捕食者”无人机为例，在虚拟现实技术的基础上，利用构造无人机模型过程中的自由度(DOF)控制技术、模型数据库优化技术和纹理映射技术等关键技术来实现对无人机动态实体模型的构建和任务飞行的模拟。对以无人机为主体的虚拟环境视景仿真建模关键技术进行研究，实现对无人机等视景仿真模型的构建、虚拟环境的建模，生成高效、优化的模型，为后续实时仿真应用以及在三维模型的优化以及地形、影像和地理信息系统(GIS)数据的相互精确匹配上，打下坚实基础。     

Response-time evaluation of transaction-oriented applications inVSAT networks

The authors present modeling of an integrated terrestrial-satellite network using very small aperture terminals (VSATs), for transaction-oriented computer applications. They address the analytical and simulation modeling techniques used to study the network performance. More specifically, these models are used to obtain network response times for an integrated terrestrial-VSAT network for inquiry-response applications under various load conditions at the cluster controller units. The major result obtained through this analytical and simulation modeling suggests that communications satellite channels can be used efficiently for the interactive inquiry-response traffic at an acceptable response time, provided that the system parameters including the link transmission rates are chosen appropriately     

直升机光电干扰仿真建模研究

对直升机光电干扰仿真建模的内容及机理进行了分析,提出了建立直升机光电干扰模型的方案、可行性及实现的途径．确定了直升机、导弹的运动学和动力学模型;干扰弹运动学模型;红外干扰机的干扰机理模型．通过对直升机光电干扰仿真建模的研究,有助于通过仿真来对光电干扰策略的干扰效果进行前期的评估。     

三维特殊效果库的研究与实现

粒子系统是在计算机图形学领域解决复杂物体建模、渲染的有效方法。针对构建三维模型库子系统——三维特殊效果库的几个关键环节的研究与实现进行了总结。这其中包括针对典型三维特殊效果进行粒子系统建模，对特殊效果库进行结构设计，以及对三维特殊效果模型的封装、存储和管理等过程。该效果库的建立为特殊效果模型的使用和重用提供了便利，对构建协同建模环境、沟通模型开发和仿真运行环境都具有积极的意义。