3-D simulation of angled strike heavy-ion induced charge collection in silicon–germanium heterojunction bipolar transistors

This paper presents 3-D simulation of angled strike heavy-ion induced charge collection in domestic silicon-germanium heterojunction bipolar transistors （SiGe HBTs）. 3D damaged model of SiGe HBTs single-event effects （SEE） is built by TCAD simulation tools to research ions angled strike dependence. We select several different strike angles at variously typical ions strike positions. The charge collection mechanism for each terminal is identified based on analysis of the device structure and simulation results. Charge collection induced by angled strike ions presents a complex situation. Whether the location of device ions enters, as long as ions track through the sensitive volume, it will cause vast charge collection. The amount of charge collection of SiGe HBT is not only related to length of ions track in sensitive volume, but also influenced by STI and distance between ions track and electrodes. The simulation model is useful to research the practical applications of SiGe HBTs in space, and provides a theoretical basis for the further radiation hardening.     

基于TMS320F28335的单极性SPWM的实现

文中介绍了应用高性能数字信号处理器（DSP）TMS320F28335输出正弦波的原理和方法,其中详细介绍了借助28335内部的正弦脉宽调制（EPWM）模块输出单臂／双臂斩波、带／不带同臂互补的四种驱动信号的方法,最后搭建实验平台对理论分析和仿真结果进行验证,实验结果表明利用该控制器的逆变系统可以输出满足工程需要的50Hz正弦波。     

压电微动平台的改进PI迟滞模型研究

为了建立既有较高精度又有较快运算速度的压电微动平台迟滞模型,对传统PI迟滞模型进行了改进研究。由于压电微动平台初载曲线前半升程斜率变化较大,而后半升程斜率变化较小,因此,采用非等分域值方法建立了其PI迟滞模型,通过求取所建模型与实测初载曲线误差的最小二范数辨识出了模型的相应参数,实验验证了所建模型的有效性。实验结果表明,在20.7μm的平台最大位移范围内,模型的最大误差为0.71μm,平均误差为0.23μm。     

DEVELOPMENT OF NEW PILL-BOX WINDOW FOR S-BAND HIGH POWER KLYSTRON简

In this paper, a new pill-box window with arc groove disk is studied for S-band high power klystron. Its main characteristics are long pill-box and periodic grooved window disk. The long pill-box window can decrease the normal field and relieve the radio frequency loss in high power transmission, and periodic grooved window disk can suppress tangential field multipactor. The Monte Carlo （MC） method is used to build up the simulation model and analyze the increasing tendency of electrons. The simulation results indicate that long-box window with periodic are grooved window disk can restrain multipactor effectively. Homocentric circular half-camber arc slot is put forward to overcome the disadvantages of periodic straight triangle and strait rectangular. The long pill-box with groove disk window prototype is tested in high power Travelling Wave Resonant Ring （TWRR） and the experi- mental results show an excellent character of this window.     

一种改进的极化敏感阵列解相干算法

在相干信号源情形下,常用的极化敏感阵列信号处理方法(如参数估计、波束形成等)会出现性能下降甚至失效的现象。该文在极化平滑算法的基础上提出一种改进的解相干算法,通过对各子相关矩阵选择适当的加权系数,使平滑之后的相关矩阵具有Toeplitz的形式,进而消除信号之间的相干性。该文推导了最优加权系数的表达式及最大解相干信号个数,并利用加权平滑之后的相关矩阵完成了参数估计和波束形成。计算机仿真结果表明改进的方法具有比常规极化平滑算法更优越的性能,且适用于非均匀噪声和相干噪声的情况。     

一种能提高DRC友好性和CMP形貌的冗余金属填充方法

化学机械研磨(CMP)被广泛用于铜镶嵌工艺,研磨后铜的厚度和表面形貌对65纳米以下的工艺显得越来越重要,厚度和形貌的变动会对芯片良率和性能造成恶劣影响,所以必须在设计时就进行慎重的考虑。众所周知,插入冗余金属是提升CMP形貌的一个好方法,通常基于规则的方法广泛用于65纳米及以上工艺中,但是该技术在比较先进制程中显示不出其优越性。本文阐述了一种基于模型的冗余金属填充方法,它是根据设计版图中的周围环境用计算机算法来填充。这一方法的优点有以下几方面:在设计规则检查(DRC)中更少的违规数量,更密集的图形密度分布和更少的填充图案数量,更小的密度和周长梯度。在使用40纳米工艺的晶圆上,基于模型方法得到的表面平坦度与基于规则的填充方法相当,但是比公开的其它填充方法要好。     

单偏振光纤激光器的研究进展

单偏振光纤激光器已成功应用于光纤传感、光纤陀螺和相干通信等领域。在阐述了光纤激光器机理和偏振理论的基础上,综述了光纤激光器基于保偏光纤、偏振控制器以及光纤布拉格光栅（FBG）等技术实现单偏振输出的方法以及近年来的研究进展,并对其进行了对比分析,提出相应的改进方案。     

Design and Validation of an Efficient Authentication Scheme with Anonymity for Roaming Service in Global Mobility Networks

Designing a user authentication protocol with anonymity for the global mobility network (GLOMONET) is a difficult task because wireless networks are susceptible to attacks and each mobile user has limited power, processing and storage resources. In this paper, a secure and lightweight user authentication protocol with anonymity for roaming service in the GLOMONET is proposed. Compared with other related approaches, our proposal has many advantages. Firstly, it uses low-cost functions such as one-way hash functions and exclusive-OR operations to achieve security goals. Having this feature, it is more suitable for battery-powered mobile devices. Secondly, it uses nonces instead of timestamps to avoid the clock synchronization problem. Therefore, an additional clock synchronization mechanism is not needed. Thirdly, it only requires four message exchanges between the user, foreign agent and home agent. Further, the security properties of our protocol are formally validated by a model checking tool called AVISPA. We also demonstrate that this protocol enjoys important security attributes including prevention of various attacks, single registration, user anonymity, no password table, and high efficiency in password authentication. Security and performance analyses show that compared with other related authentication schemes, the proposed scheme is more secure and efficient.     

各向异性材料涂覆目标电磁散射特性仿真

该文基于阻抗边界条件(IBC),提出了3维各向异性材料涂覆目标电磁散射特性的矩量法(MoM)解决方案。根据表面等效原理,采用感应电磁流以3维RWG(Rao-Wilton-Glisson)矢量基函数展开的伽略金法。以表面阻抗矩阵表征电磁参数,实现各向异性材料涂覆目标的电磁仿真,算例结果与Mie级数解等精确结果吻合良好。对各向异性材料涂覆复杂目标的电磁散射特性进行分析,为目标的雷达隐身和反隐身提供理论支持。     

车载移动立体测量系统检校及精度分析

车载移动立体测量系统可以用于快速、准确的高精度数据采集和三维建模。针对车载移动立体测量检校问题,设计了一套高精度的车载移动立体测量系统检校方法,建立了检校的数学模型,并进行了试验,分析了检校前后车载移动立体测量系统的测量精度差异。实验证明,本文研究的车载移动立体测量系统检校方法能有效地提高系统测量精度。