一种新型光插分复用器

介绍了一种新型光插分复用器(OADM),它由两个特殊设计的双芯光纤和单芯光纤组成的耦合器构成,耦合器之间用双芯光纤连接,光纤内写有光纤光栅.详细分析了该器件的工作过程,总结了其性能和优点.     

光纤数字图像传输模块的研制

研制了一种采用光纤(缆)连接的数字视频接口,即光纤数字图像传输模块,采用该模块可以对图像进行远距离数字化传输.简述了其工作原理,介绍了模块研制过程中的各项关键技术,给出了实验结果并对其进行了讨论.     

用于太阳能光纤照明系统的空心反共振反射光纤

分析反共振反射光纤的导光机理和传输特性的基础上,提出了一种新型的空心反共振反射光纤.通过传输矩阵法计算此种光纤的传输特性,证明这种新型的光纤更适合太阳能光纤照明系统的光线传送,为太阳光的传输提供了一种新余径.     

音频信号传输系统的数字化光纤改造

数字化和光纤传输是目前通讯领域发展的重点方向.本文介绍了一例广播发射台站对广播节目音频信号的传输系统进行数字化光纤改造项目,该项目从实际出发,立足台站自身技术力量,解决了原模拟信号传输质量不佳,衰减大、频响差的缺陷,实现了音频信号全数字化传输.     

光子晶体光纤及其在传感器中的应用

光子晶体光纤(PCF)是一种新型光纤,其结构和导光机理都与普通光纤不同,呈现出许多在传统光纤中难以实现的特性,并因此受到广泛关注.PCF具有的特殊的性质扩大了光纤的应用领域.利用PCF的某些特性,可以制作性能优良的传感器.文章首先介绍了PCF的基本概念和主要特性,然后介绍了PCF在传感方面的几种应用.     

一种新型的可重构光分插复用器件的设计

设计了一种带四根单模尾纤的光纤准直器,基于这种四光纤准直器及介质薄膜滤波器,提出了一种新型的可重构光分插复用器件的设计方案.该器件只用一个四光纤准直器,输入光纤、输出光纤和分下/插入光纤都分布在器件的同侧,具有体积小、成本低、信道隔离度高等优点.     

傅立叶域锁模光纤激光器的研究新进展

傅立叶域锁模( FDML)光纤激光器是目前激光领域中比较有活力的研究课题,有着巨大的应用前景.在介绍了FDML光纤激光器的发展状况和应用前景基础,论述了其基本原理,对其关键技术及多种新型技术方案做了介绍和比较,分析FDML光纤激光器的应用前景及发展趋势.     

高功率光纤飞秒激光放大器的研究现状与发展趋势

针对高功率光纤飞秒激光放大器,介绍了啁啾脉冲放大(CPA)技术的基本原理,讨论了该结构中关键的展宽器和压缩器的发展现状与瓶颈;介绍了典型的大模场面积光纤的结构和工作原理,简介了基于大模场面积光纤的CPA系统的发展现状;介绍了非线性放大技术,讨论了实现更窄脉冲宽度、更高脉冲质量的光纤飞秒激光放大方案;最后分析了全光纤结构、相干合束、单晶光纤增益介质以及皮秒种子源等新型技术,并总结了高功率光纤飞秒激光放大器的发展趋势。     

基于F-P滤波器的光纤光栅解调系统的优化设计

为了提高基于法布里-珀罗(Fabry-Perot,F-P)滤波器的光纤光栅波长解调系统的性能,提出了一种采用新型光纤梳状滤波器作为参考波长装置的解调方案.新型光纤梳状滤波器由两个啁啾光栅和一个光耦合器组成,与传统的参考光栅相比可以为解调系统提供更多的参考点.优化后的解调系统重复性好,运行更稳定、精确.     

一种新型光纤光栅无线传感网络及路由设计

传统的光纤光栅传感网络具有灵活性低、移动性差等缺点.文章作者构建了一种新型的光纤光栅无线传感网络,该网络融合了无线通信和光纤光栅传感的优点.同时还设计了节点结构,并根据实际应用场景提出了该传感网络的路由协议--RT(路由选择表)协议.在NS2(Network Simulator)中,从分组投递率、时延和能耗等3方面与Flooding协议进行了比较分析,结果显示RT协议更适合该新型传感网络.     

Voltage difference engineering in SOI MOSFETs: A novel side gate device with improved electrical performance

We studied the impact of voltage difference engineering in a silicon-on-insulator metal oxide semiconductor field-effect transistor (SOI-MOSFET) and compared the performance to that of a conventional SOI-MOSFET (C-SOI). Our structure, called a SIG-SOI MOSFET, includes main and side gates with an optimum voltage difference between them. The voltage difference leads to an inverted channel as an electrical drain extension under the side gate. This channel creates a stepped potential distribution along the channel that it cannot be seen in the C-SOI MOSFETs. The voltage difference controls the channel properly and two-dimensional two-carrier device simulations revealed lower threshold voltage variations, larger breakdown voltage, higher voltage gain, lower hot carrier effects, improved drain-induced barrier lowering, lower drain conductance, higher unilateral power gain, and lower leakage current compared to a C-SOI device. Thus, our proposed structure has higher performance than a typical C-SOI structure.     

电子式电流互感器的高压侧供电电源设计

电子式电流互感器的高压侧电路供电问题是其研制的一个难点。设计了一种用于电子电流互感器高压侧供电的激光电源,实验表明该电源性能良好,可作为高压侧电子线路的供能装置。     

改进型带隙基准电压源设计

传统带隙基准源结构能输出比较精确的电压,但其电源电压较高,要在较低的电源电压下得到更低电压的基准电压,就必须对基准源路结构进行改进和提高.本文提出了一种改进型的带隙基准电压源设计,可以输出较低的基准电压,基本能够满足复杂苛刻的工业生产环境的需求.     

Multiphase Bidirectional Flyback Converter Topology for Hybrid Electric Vehicles

For hybrid electric vehicles, the batteries and the drive dc link may be at different voltages. The batteries are at low voltage to obtain higher volumetric efficiencies, and the dc link is at higher voltage to have higher efficiency on the motor side. Therefore, a power interface between the batteries and the drive's dc link is essential. This power interface should handle power flow from battery to motor, motor to battery, external genset to battery, and grid to battery. This paper proposes a multi-power-port topology which is capable of handling multiple power sources and still maintains simplicity and features like obtaining high gain, wide load variations, lower output-current ripple, and capability of parallel-battery energy due to the modular structure. The scheme incorporates a transformer winding technique which drastically reduces the leakage inductance of the coupled inductor. The development and testing of a bidirectional flyback dc-dc converter for hybrid electric vehicle is described in this paper. Simple hysteresis voltage control is used for dc-link voltage regulation. The experimental results are presented to show the working of the proposed converter.     

A highly efficient class-EF<Subscript>2</Subscript> power amplifier in GaAs pHEMT technology

This paper presents a highly efficient class-EF₂ power amplifier in GaAs pHEMT technology with high output power. Drain swing voltage of class-E power amplifier (PA) imposes a restriction on its output power. In this work, using a combination of class-E and F relaxes this limitation which may help in increasing DC supply voltage. Higher DC supply voltage of class-EF₂ PA leads to increased output power and efficiency, as output power is proportional to supply voltage. In addition, higher supply voltage permits PA to work under lower current which can cause to reduce power dissipation. Proposed class-EF₂ PA is implemented in a single recess AlGaAs–InGaAs pHEMT technology with 0.25-µm gate length; power added efficiency of 52% at 31 dBm output power is achieved at 1.8 GHz.     

光学玻璃型电流互感器光源温度控制器设计

介绍了光学玻璃ECT光源温度控制器的工作原理。针对光学玻璃ECT对光源光强输出及其中心波长稳定性的特殊要求,提出了基于大功率调压控温,叠加脉冲细微调节光源温度的控温思想。介绍了支撑该思想的硬件电路。测试结果表明,在-40~+70 ℃的工作环境范围内,光学玻璃ECT光源温度能够控制在+25±0.1 ℃,也证明了该控温设计的正确性。     

A multimodule parallelable series-connected PWM voltage regulator

This paper presents the analysis and design of a single-phase voltage regulator (VR) and its multinodule parallel control. The VR employs the pulsewidth modulation three-arm rectifier-inverter topology. The inverter side adjusts the load voltage with the series regulating structure aiming to minimize converter capacity and attain higher efficiency. The rectifier side regenerates the load power and executes the active power filter function to achieve unity power factor. Based on such high-performance VR, a resistive droop method combined with the P-V droop and Q-δ shift scheme is then proposed to control the current sharing such that multiple VRs can be paralleled directly without any control interconnection. The proposed parallel control technique possesses the features of fast response, precise voltage regulation, equal fundamental and harmonic current sharing, tolerance for parameter mismatch, and so on. Two prototype 1 KVA VRs are implemented, and the effectiveness is demonstrated by some simulation and experimental results     

Low voltage Manchester adder design

A low voltage dynamic Manchester adder design is presented, with a critical delay path operating at a higher voltage level. This voltage level is generated on-chip using a bootstrapping circuit. The goal of this design is to maintain the delay of its worst-case path, comparable to the design having a higher supply voltage, while operating the rest of the circuit at a lower supply voltage, thus consuming less overall power. A SPICE simulation is performed to verify the design     

Integral motor with driver and wireless transmission of power andinformation for autonomous subspindle drive

This paper describes the novel technology of an integral motor with the associated driver and wireless transmission of power and information (WTPI), which is effectively applied to autonomous spindle drive for the sophisticated workpiece machining. The power supply to the integral motor is made by way of a separable WTPI coupling. In addition, calculation for variable voltage and variable frequency (VVVF) control is done at the primary side of the coupling, and then the frequency command is transmitted to the secondary side by an overlapped transmission of the data on the power transmission through the WTPI coupling. At the secondary side, direct power conversion from the induced high-frequency voltage to the motor terminal voltage is conducted using a bidirectionally controllable power switch. The amplitude of the terminal voltage is adjusted by changing the inverter voltage at the primary side. In this way, the VVVF drive is made through the WTPI coupling, thus providing the integral subspindle with the autonomy for sophisticated machining     

The matrix converter drive performance under abnormal input voltage conditions

The matrix converter (MC) is a direct frequency conversion device with high input power quality and regeneration capability. As a device without energy storage elements, it has higher power density than pulse-width modulation (PWM) inverter drives. However, for the same reason, the AC line side disturbances can degrade its performance and reliability. In this paper, the behavior of the MC drive under abnormal input line voltage conditions has been investigated. A technique to eliminate the input current distortion due to the input voltage unbalance has been developed and its feasibility proven via computer simulations and laboratory experiments. The power line failure behavior has also been investigated and the rapid restarting capability of the MC drive has been demonstrated via laboratory experiments.