Impact of gain saturation on size limitations of semiconductorlaser amplifier (SLA) based switching structures

Size limitations of optical switching structures employing semiconductor laser amplifiers arising from signal extinction ratio, amplifier gain, and optical filter bandwidth are investigated theoretically and experimentally. Simulations reveal that the maximum number of SLA that can be cascaded in an optical switching structure increases with increasing input signal extinction ratio, optical gain of each SLA and decreases with increasing SLA noise figure, optical filter bandwidth and input signal bit rate     

Resistive switching characteristic of electrolyte-oxide-semiconductor structures

The resistive switching characteristic of SiO₂ thin film in electrolyte-oxide-semiconductor (EOS) structures under certain bias voltage is reported. To analyze the mechanism of the resistive switching characteristic, a batch of EOS structures were fabricated under various conditions and their electrical properties were measured with a set of three-electrode systems. A theoretical model based on the formation and rupture of conductive filaments in the oxide layer is proposed to reveal the mechanism of the resistive switching characteristic, followed by an experimental investigation of Auger electron spectroscopy (AES) and secondary ion mass spectroscopy (SIMS) to verify the proposed theoretical model. It is found that different threshold voltage, reverse leakage current and slope value features of the switching I-V characteristic can be observed in different EOS structures with different electrolyte solutions as well as different SiO₂ layers made by different fabrication processes or in different thicknesses. With a simple fabrication process and significant resistive switching characteristic, the EOS structures show great potential for chemical/biochemical applications.     

Polyhedral switching structures for ATM networks

The authors propose switching structures based on regular and non-regular polyhedra which ensure better QoS than the ATM switching networks known to date. The key idea of this solution is based on placing elementary switches on a sphere-shaped surface. Any set of adjacent switches forms a polygon, and the polygons in turn form a polyhedron     

Electrical characteristics of silicon-rare-earth fluoride layered switching structures

Switching and memory effects in the electrical conductance of layered structures based on rare-earth fluorides are investigated. These investigations reveal the existence of high-and low-resistance states in structures of metal-insulator-semiconductor type. It is shown that the characteristics of the low-resistance state of such structures are described by a metal-tunneling insulator-semiconductor model. Fiz. Tekh. Poluprovodn. 32, 1349–1353 (November 1998)     

多平面ATM交换网络结构及其性能分析

本文提出一种新的多平面ＡＴＭ交换网络结构。该结构比单平面结构有更好的性能,并且在网络平扩容和冗余备份等方面均具有优良的特性。通过采用虚拟队列和概率母函数的方法,分析了在随机均匀业务模型下该交换网络缓存器的平均队长、平均信元时延和交换网络最大吞吐率等性能参数的封闭表达式,计算机仿真结果表明了分析结果具有很高的精确度。该分析方法不需复杂的叠代算法,在交换机的工程设计中同时也具有重要的实际意义。     

Dynamic power density, wavelength, and switching time modulation of optically triggered power transistor (OTPT) performance parameters

Optical modulation by varying the intensity, wavelength, or switching time can dynamically alter the performance parameters of direct optically controlled power semiconductor device. Understanding the effect of optical parameters on these parameters from a first principle approach is necessary for making optimal design choices and gaining design insights. We focus on performance parameters whose variations with direct optical modulation have not been reported previously for a power semiconductor such as switching times and on-state resistance. We carry out analytical modeling and two-dimensional (2D) finite-element simulations for a GaAs/AlGaAs based superjunction lateral optically controlled power transistor that has been fabricated and successfully tested for high-voltage capability. It is shown that optical power density can modulate on-state resistance and more importantly the trade-off curve between breakdown voltage and on-state resistance. A closed-form analytical equation relating switching times with optical parameters via logarithmic function is derived and the nonlinear variation of on-state resistance and switching time with optical wavelength is illustrated. We also derive the analytical expression for power device rise time as a function of optical signal rise time and show that they are related by Lambert's W-function with exponential coefficients.     

High-speed optoelectronic switching in silicon gap-shunt microstrip structures

A new silicon microstrip device for high-speed optoelectronic switching and gating of d.c. or r.f. signals up to the gigahertz range, using a combined gap-shunt microstrip structure, is reported. The switching actions are achieved via laser-excited highly conductive solid-state plasmas     

光分组交换技术的研究

光分组交换技术的引入，改善了带宽的利用率和网络的灵活性，延伸了光的透明性。在光分组交换层中光分组的产生、同步、缓存、再生，分组头重写及分光组之间挑功率的均衡成为实现光分组产换的基本技术，而多波长方案并不是光分组交换的唯一模式，光时分分组交换、光标签交换、波分及混合分组交换、多协议标签交换、光突发分组交换等交换方式的出现必将对未来的通信网产生重要的影响。     

一种新型光交换技术:光码标签突发包交换

一种新型光交换技术-光码标签突发包交换技术。该技术是光突发包交换与光码标签交换的结合体，具有两者的共同优点，是一种性能优良的光交换技术。本文首先介绍了该技术的原理，然后给出了网络节点功能结构的设计，最后讨论了该技术的性能。     

Real-time packet switching: a performance analysis

The authors model the internal structure of a packet-switching node in a real-time system and characterize the tradeoff between throughput, delay, and packet loss as a function of the buffer size, switching speed, etc. They assume a simple shared-single-path switch fabric, though the analysis can be generalized to a wider class of switch fabrics. They show that with a small number of buffers the node will provide a guaranteed delay bound for high-priority traffic, a low average delay for low-priority traffic, no loss of packets at the input and low probability of packet loss at output     

Improved feeding structures to enhance the performance of the reflector impulse radiating antenna (IRA)

This paper considers the improvement of the feeding structure of the reflector impulse radiating antenna (IRA). Full-wave analysis and measured results of the orthogonal cross-coplanar plate reflector IRA shows that the aperture fields are not uniform. The arm angle is varied as an optimization factor and it is shown that the arm angle of 70/spl deg/ has the maximum radiation efficiency. The termination load and the arm tapering effects are studied using simulation and measurement results. Furthermore, the effect of radius of circle of symmetry is studied and it is shown that a greater circle provides higher gain. A combination of transverse electromagnetic (TEM) horn antenna and the conical coplanar TEM transmission line is investigated to avoid tiny structure at the focal point and make the connection between the coaxial cable and the feeding arms more convenient. It is shown that a small triangle does not degrade the antenna performance but helps to excite the antenna by a coaxial cable. Finally a combination of the Vivaldi antenna and the coplanar transmission line is introduced to improve the antenna performance. The simulation results for the new antenna show that the antenna efficiency is improved to 45% at the frequency band between 2 GHz to 6 GHz in comparison to the 20.9% for the traditional design and 29.7% for the tapered design. The calculated far-field results of all these antennas are used to radiate a 0.5 ns impulse. The radiated impulse from the Vivaldi fed reflector IRA is 3.55, 2.41, and 2.12 dB higher than the same radiated impulses from the reflector IRA fed by a 45/spl deg/ traditional feeding arms, 70/spl deg/ traditional feeding arms, and 70/spl deg/ tapered feeding arms, respectively.     

波带交换新算法及其性能分析

由于波带交换在减少交换结构端口数、降低控制面复杂度和光交叉连接费用方面具有实际的意义,因而引起了人们广泛的关注.文章提出了两种新的波带交换算法并且做了相应的性能分析.     

KS8993型高性能交换电路及其应用

KS8993是美国KENDIN公司开发的包含3端口10/100物理层收发器的高性能快速以太网交换电路.详细介绍KS8993的主要功能、特点和主要接口,给出了KS8993在IP电话中的应用实例.     

Closed-loop performance comparisons of switching regulators withcurrent-injected control

The authors verify the validity of applying state-space averaging and linearization to the control law of current-injected switching regulators for designs with wideband first-order open-loop responses without right-hand plane (RHP) zeros. Quantitative closed-loop performance comparisons are made of current-injected versus voltage control for the boost and buck switching regulator topologies. In buck-topology regulators, current-injected control implemented using pole cancellation, does not yield categorically better closed-loop performance than what is obtained by using lead compensated voltage control. For the boost regulator, the advantages of current-injected control are greater since lead-compensation cannot usually be used due to the duty-factor-dependent complex pole and RHP zero     

An architecture of scalable ATM switching system and its performance

In this paper, we present the basic idea and some concepts for the architecture of the ATM switching system being developed in ETRI of KOREA, and also describe its performance. RSE (Reference Service Entity) concept is introduced to define the characteristics of user’s traffic. This concept is useful to represent the demand of CPE (Customer Premise Equipment) user sets and one of point‐to‐multipoint connections. We also propose RUCA (Reference Units for Connection Attempts) concept with which we can illustrate the call/connection level performance of the ATM switching system. This concept can be applied for measuring the call processing capability in both point‐to‐multipoint connections and multipoint‐to‐multipoint connections when call set‐up between users is performed by a sequence of point‐to‐point connections basis. From the basic concepts and the recommendations of ITU‐T, the design objective of the system performance is specified. We represent the methodologies for dimensioning the system to achieve the design objectives, and estimate the system performances. Then we show that our developing system has suitable performance to accommodate the future B‐ISDN. This revised version was published online in August 2006 with corrections to the Cover Date.     

硅基光子交换芯片的路由控制与性能测试

设计了电压输出范围分别是0~10 V和0~2V、调节精度为10mV的可扩展热 控电路和电控 电路,用于实现16×16光子集成芯片的工艺误差补偿和光开关切换。 描述了由硅(Si)基马赫-曾德尔(MZI)光开关单元组成的16×16光 子集成芯片控制过程,提出了基于光开关传输性能的改进环路 路由算法,此算法适用于光开关性能劣化或局部出现故障的情形。搭建了运行有改进路由算 法的光交换芯片测试系统,实验 结果表明,芯片模块的插入损耗小于33dB,串扰小于－10dB,能够实现无误码传输要求。     

Photolectric effects in silicon switching structures utilizing rare-earth fluorides

The photoelectric characteristics of silicon metal-insulator-semiconductor switching structures are investigated; cerium, dysprosium, and erbium fluorides are used for the insulator layer. It is shown that the photoelectric characteristics of the structures in the low-resistance state are similar to those of a metal-(tunneling insulator)-semiconductor structure; in particular, a mechanism of injection amplification of the photocurrent comes into play. Fiz. Tekh. Poluprovodn. 33, 795–800 (July 1999)     

Survey of switching techniques in high-speed networks and their performance

One of the most promising approaches for high speed networks for integrated service applications is fast packet switching, or ATM (asynchronous transfer mode). ATM can be characterized by very high speed transmission links and simple, hard-wired protocols within a network. To match the transmission speed of the network links, and to minimize the overhead due to the processing of network protocols, the switching of cells is done in hardware switching fabrics in ATM networks. A number of designs have been proposed for implementing ATM switches. Although many differences exist among the proposals, the vast majority of them are based on self-routeing multistage interconnection networks. This is because of the desirable features of multi-stage interconnection networks such as self-routeing capability and suitability for VLSI implementation. Existing ATM switch architectures can be classified into two major classes: blocking switches, where blockings of cells may occur within a switch when more than one cell contends for the same internal link, and non-blocking switches, where no internal blocking occurs. A large number of techniques have also been proposed to improve the performance of blocking and non-blocking switches. In this paper, we present an extensive survey of the existing proposals for ATM switch architectures, focusing on their performance issues.     

The enumeration method for selecting optimum switching network structures

In this paper it is shown that traditional continuous optimization methods for multistage switching networks may fail, leading to nonoptimal structures. Then, a simple enumeration method to solve the optimization problem is proposed. The numerical examples show that the parameters of optimum networks can be calculated very fast for any practical network sizes.