一种新型电子节能灯用晶体管——双极型静电感应晶体管

本文简要叙述了开发和研制ＢＳＩＴ的市场背景和技术现状，对ＢＳＩＴ器件模型进行了理论分析，对ＢＳＩＴ器件的设计和制作工艺进行了探讨，并分析了ＢＳＩＴ器件的工作原理和特性；介绍了ＢＳＩＴ器件的应用和上灯试用情况。     

双极型静电感应晶体管开关时间的测量与分析

从理论和实验两方面对静电感应晶体管（ＢＳＩＴ）的开关时间进行了分析和测量，提出了简单的分析方法，将影响ＢＳＩＴ开关时间的各个因素归结为结构因子和材料因子，从而简化了分析影响ＢＳＩＴ开关时间的因素，对于ＢＳＩＴ的实际工艺，结构设计有指导意义。     

BSIT开态的数值分析

对双极模式静电感应晶体管开通过程的理论分析和二维数值模拟清楚地表明，ＢＳＩＴ的完全开通须经过不同作用机制的两个阶段的转变，即正向小栅压下的势垒控制机制转变为大栅压下的少子注入电流控制机制。数值计算给出的结果有：小栅压下沿沟道中心线的电势分布；沿沟道的少子和电场分布；开态的Ｉ－Ｖ特性；通态压降和饱和电流随正栅压的变化；通态电阻随栅压和材料参数的变化；特别是电流增益随栅压、漏电流以及材料参数的变化。上     

双极型静电感应晶体管的温度特性

通过双极型静电感应晶体管（ＢＳＩＴ）与普通双极型晶体管（ＢＪＴ）温度特性的对比，研究ＢＳＩＴ的温度特性。由实验看出，影响ＢＳＩＴ温度特性的主要因素是载流了迁移率μ和邮源极越过势垒的电子数目ｎ。以盯可解释几个在观察ＢＳＩＴ温度特性时所遇到的现象。     

宽温高频高反压沟道项区晶体管研制

耗尽是基区双极晶体管也称为双极静电感应晶体管（ＢＳＩＴ），基电流放大系数（ｈＦＥ）具有负的温度系数。双极结型晶体管（ＢＪＴ）的ｈＦＥ具有正的温度系数，将ＢＳＩＴ与ＢＪＴ并联，采用ＢＪＴ常规平面工艺制造了宽温高频高反压沟道基区双极ＰＮＲ晶体管。本文描述了这种瓣器件结构、工作原理、设计与制造。新器件突出特点是：当温度变化较大时，ｈＦＥ漂移较小。测试结果表明：环境温度从２５℃升到１８０℃时，器件的ｈＦＥ     

GexSi1-x合金基区异质结晶体管模拟器——GSHBT

基于有限差分法开发了一个ＧｅｘＳｉ－ｘ合金基区异质结晶体管（ＧｅｘＳｉ－ｘＨＢＴ）模拟器ＧＳＨＢＴ。通过解释一组输入语句,ＧＳＨＢＴ可模拟任意掺杂分布和锗分布的ＧｅｘＳｉ－ｘＨＢＴ的直流特性、频率特性和器件的内部图像。文中描述了ＧＳＨＢＴ的特点和使用方法,阐述了进行器件特性分析的数值方法,并给出了应用实例。     

激光制备多层铁电薄膜的C—V保持特性研究

采用脉冲准分子激光工艺在Ｓｉ（１００）单晶基片上，成功地淀积了ＢＩＴ、ＰＺＴ／ＢＩＴ和ＢＩＴ／ＰＺＴ／ＢＩＴ等多层结构的铁电薄膜。通过测量金属／ＢＩＴ／ＰＺＴ／ＢＩＴ／Ｓｉ多层结构的非回线型Ｃ－Ｖ特性曲线、电容与保持时间的关系，发现三层ＢＩＴ／ＰＺＴ／ＢＩＴ薄膜具有很好的电容保持特性，是铁电场效应晶体管的理想栅极材料     

HBI中基区内建电场的物理机制及其理论分析

计算了具有线性Ｇｅ分布的ＳｉＧｅ基区价带有效态密度和空穴浓度的分布，分析了基区内建电场的物理机制，分别采用Ｂｏｌｔｚｍａｎ统计和Ｆｅｒｍｉ－Ｄｉｒａｃ统计给出了内建电场分布的表达式并进行了计算，最后讨论了基区重掺杂对电场的影响。     

Si／SiGe／Si HBT的优化设计

给出了常温和低温Ｓｉ／ＳｉＧｅ／ＳｉＨＢＴ的设计原则，并进行了讨论。指出了低温和室温ＨＢＴ设计上的差异。这些原则可用于设计特定要求的Ｓｉ／ＳｉＧｅ／ＳｉＨＢＴ。     

激光制备多层薄膜及铁电性能的研究

利用脉冲准分子激光淀积（ＰＬＤ）方法，在Ｓｉ基片上制备了ＢＩＴ／Ｓｉ〔１００〕、ＰＺＴ／ＢＩＴ／Ｓｉ〔１００〕和ＢＩＴ／ＰＺＴ／ＢＩＴ／Ｓｉ〔１００〕铁电薄膜。用ＸＲＤ分析了多层铁电薄膜的晶相结构；用Ｓａｗｙｅｒ－Ｔｏｗｅｒ电路研究了这些单层和多层铁电薄膜的铁电性能。结果表明，单层ＢＩＴ的矫顽场Ｅｃ为４ｋＶ／ｃｍ，剩余极化强度为３．４μＣ／ｃｍ２；ＰＺＴ／ＢＩＴ的矫顽场Ｅｃ为８２ｋＶ／ｃｍ，剩余极化强度Ｐｒ为３６μＣ／ｃｍ２；ＢＩＴ／ＰＺＴ／ＢＩＴ夹层铁电薄膜的矫顽场Ｅｃ为５７ｋＶ／ｃｍ，剩余极化强度Ｐｒ为２９μＣ／ｃｍ２。最后讨论了薄膜的铁电性能与多层结构的关系     

Optimisation of two-stage Raman converter based on phosphosilicatecore fibre: modelling and experiment

Parameter optimisation of a two-stage Raman converter based on phosphosilicate-core fibre is presented. The optimal operational regime is determined and its tolerance against variations of laser parameters is examined. Results of numerical modelling are in a good agreement with experimental data     

反辐射武器作战效能的一种评估方法

首先建立了反辐射武器作战效能评估的模型,讨论了影响作战效能的相关因素,并给出了一个利用动态规划数值方法求解的计算实例,得到了反辐射武器对目标毁伤的效能值。结果表明合理的火力分配能提高反辐射武器的整体作战能力。     

Combinatorial methods for the evaluation of yield and operational reliability of fault-tolerant systems-on-chip

In this paper we develop combinatorial methods for the evaluation of yield and operational reliability of fault-tolerant systems-on-chip. The methods assume that defects are produced according to a model in which defects are lethal and affect given components of the system following a distribution common to all defects; the method for the evaluation of operational reliability also assumes that the fault-tree function of the system is increasing. The distribution of the number of defects is arbitrary. The methods are based on the formulation of, respectively, the yield loss and the operational unreliability as the probability that a given Boolean function with multiple-valued variables has value 1. That probability is computed by analyzing a ROMDD (reduced ordered multiple-value decision diagram) representation of the function. For efficiency reasons, a coded ROBDD (reduced ordered binary decision diagram) representation of the function is built first and, then, that coded ROBDD is transformed into the ROMDD required by the methods. We present numerical experiments showing that the methods are able to cope with quite large systems in moderate CPU times.     

Interval-availability distribution of 2-state systems withexponential failures and phase-type repairs

Interval availability is a dependability measure defined as the fraction of time during which a system is in operation over a finite observation period. Usually, for computing systems, the models used to evaluate interval availability distribution are Markov models. Numerous papers using these models have been published, and only complex numerical methods have been proposed as solutions to this problem even in simple cases such as the 2-state Markov model. This paper proposes a new way to compute this distribution when the model is a 2-state semi-Markov process in which the holding times have an exponential distribution for the operational state and a phase-type distribution for the nonoperational one. The main contribution of this paper is to define a new algorithm to compute the interval availability distribution for systems having only one operational state. The computational complexity depends weakly on the number of states of the system, and sometimes it can deal also with infinite state spaces. Moreover, simple closed expressions of this distribution are shown when repair periods are of the Erlang type with eventually absorbing states     

Selection of diversity and modulation parameters for Nakagami fading channels to jointly satisfy outage and bit error requirements

Outage events occur when the instantaneous signal-to-noise ratio or bit error rate fall into an unacceptable operational regime. Outage performance analysis is traditionally carried out for diverse channel behaviors and transmission techniques, leaving the identification of unacceptable operational regime to user specified performance requirements. An alternative approach is taken in this work and an acceptable combination of system parameters are identified such that the user specified quality of service (QoS) constraints are satisfied. The QoS constraints are specified jointly in terms of outage probability, outage duration and probability of occurrence of errors during the outage event. This work presents inter-dependencies between the QoS constraints and modulation, diversity and signal parameters in closed form. The analysis assumes identically, independently distributed Nakagami interferers using maximal ratio diversity combining (MRC).     

半导体单量子点增益与吸收特性的研究

采用密度矩阵的方法进行数值模拟计算紧束缚态的半导体单量子点的增益与吸收行为.其动力学数值结果显示,在某些不同时刻的增益谷和吸收峰的左右分布保持不变对称性,且有上下镜像反转的现象发生;在在长时间演化中发现该量子点系统的增益与吸收发生激烈的振荡而呈现出了量子光学中典型的崩塌与复苏的有趣物理现象.     

应用PO-AI方法分析加罩OAM天线的辐射特性

应用物理光学-口面积分（PO-AI）方法,数值分析加载天线罩的轨道角动量（OAM）波天线的辐射特性,评判介质天线罩对各阶模式OAM波的辐射特性、幅相分布以及模式纯度的影响程度。通过与现有文献中天线罩实例的测试值相对比,验证了算法的正确性和有效性;考察了开口波导环形阵列OAM波天线工作于不同的模式阶数时,半球形天线罩所引起的空间场幅-相分布的变化。在此基础上,计算了一个正切卵形、多层介质天线罩情况,验证了PO-AI 算法对复杂结构的适应性。从数值结果可见,天线罩对高阶OAM辐射波的幅值分布影响较大。数值计算也证实该算法可以快速预估介质罩存在时OAM波形的畸变程度,有助于实现对天线罩各参数的快速优化。     

量子密钥分配系统中非线性偏振耦合的研究

受传输光纤非线性偏振影响,量子密钥分配系统本振光与信号光耦合率下降,使形成偏振复用信号的抖动增强,系统的稳定性和安全性下降.为了提高量子光学中偏振编码技术的性能,经过理论分析和数值模拟,给出可操作性的实验方案,解决了光纤非线性偏振耦合导致的偏振抖动问题.结果表明,在同等条件下,以分光检测结果反馈控制本振光和信号光的非线性偏振耦合率,可增强偏振复用信号的稳定性,将系统传输容量提高61%.该结果有利于偏振编码技术在量子密钥分配系统的实际应用.     

Coverage Modeling and Optimal Maintenance Frequency of an Automated Restoration Mechanism

In this paper, the coverage modeling of an automated restoration mechanism with two components is studied, and optimal maintenance frequencies are determined. Failures and repairs are exponentially distributed for the two components, while the failures of the automated mechanism follow a Weibull distribution. A corrective maintenance policy is considered for each component whereas, for the automated restoration mechanism, an additional preventive maintenance is taken into account. The system is modeled with a continuous time Markov chain and two performability indicators: one performability indicator modeling the downtime, and a second one modeling the overall operational cost. Consequently, two optimal maintenance frequencies are derived: first by minimizing the downtime, and second by minimizing the overall operational cost. A numerical example is used to evaluate the applicability of the proposed method.