激光电源脉冲功率切换电路仿真分析

激光电源脉冲功率切换电路稳定工作是电源可靠性的保证。电路参数选取直接影响晶闸管、二极管的工况,而晶闸管的良好工况是保证切换激光电源长期可靠运行的基本条件。基于PSCAD软件建立切换电路的仿真模型,重点仿真分析了阻容电路参数配置、限流电阻、并联晶闸管触发同步性对晶闸管和二极管的影响。仿真结果表明,电流上升率过大是晶闸管门极损坏的原因,关断支路中的反向过压是二极管损坏的原因。并针对实际电路,提出晶闸管二极管保护的优化配置方案。     

The design and development of a 140GHz beam-lead diode subharmonically pumped mixer

The possibility of using beam-lead diodes in the design of a 140GHz subharmonically pumped mixer was investigated. An easily assembled, rugged mixer structure was developed which avoids the problems associated with present production techniques and reduces costs. The construction of the circuit developed makes it ideally suited to space and other environmentally demanding application. Computer analysis techniques were used to predict millimetre-wave performance and a large-scale low-frequency model was used to optimize the circuit. The millimetre-wave mixer was constructed using a circuit implemented on suspended substrate stripline. Results of millimetre-wave performance are presented.     

Ka/Q band GaAs IMPATT amplifier technology

GaAs IMPATT diodes are capable of generating 2 to 3 W simultaneously with 18–22% efficiency in the 33 GHz to 46 GHz frequency band. The design of the amplifier circuits which utilize these devices is discussed. The circuit design is based on a 3-step closed form algorithm. The first step is a passive circuit characterization with an automatic network analyzer. In the second step, a computer is used to generate diode device lines. The third step is load line synthesis for predictable operation. The resulting performance is described. 2 W over a 2GHz bandwidth was achieved simultaneously with a minimum gain of 12 dB.     

Transparent p‐NiO/n‐ZnO diodes used in circuit rectifiers

We report on the fabrication of a transparent photostable cell circuit composed of drive and resistor diodes which are face‐to‐face connected to each other with different device area. The diodes consisted of e‐beam evaporated p‐NiO on sputter‐deposited n‐ZnO for p/n diode formation on indium‐tin‐oxide glass. Our transparent diodes show photostable rectifying behavior, about 10³ on/off current ratio and even dynamic rectification at a maximum frequency of 100 Hz AC input signal in ambient light. The noticeable photo‐responsivity of the circuit was obtained only under ultraviolet (UV) light. We conclude that our transparent diode circuit is promising in enriching the field of transparent device electronics. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

用电流源法测量非线性元件的伏安特性

本文报导了一种新的用于测量非线性元件伏安特性的实验电路，该电路采用的是以电流为信号变量的电流模式测量电路，并分析与比较了该电路与传统的以电压作为信号变量的电压模式测量电路的不同．     

A Novel Circuit Architecture for High Performance of High-order Subharmonic Mixers

A novel circuit architecture for high performance of high-order subharmonic (SH) mixers is proposed in this paper. According to the specified harmonic mixing order, one or more mixer diodes sub-arrays and corresponding power divider as well as phase shift network for RF and LO signals are arranged in the circuit. This proposed SH mixer circuit has improved conversion loss, wide dynamic range and high port isolation for high-order SH mixers. By phase cancellation of idle frequencies, the proposed SH mixer circuit can eliminate complicated design procedure of idle frequency circuits; by phase cancellation of leakage LO power to RF and IF port, and leakage RF power to LO port, the mixer circuit can get high port isolation in LO-IF/RF and RF-LO. The increased antiparallel diode pairs in each sub-array will also lead to well performance by lowering effective series resistance. The proposed SH mixer circuit can be easily realized with power divider and phase shift network for RF and LO signals. Supported in part by National Natural Science Foundation of China (NSFC) under Grants 60621002 and in part by NSFC under Grants 60471017.     

Chaos via torus breakdown from a four-dimensional autonomous oscillator with two diodes

By using a remarkably simple and natural degenerate technique, the mechanism of chaos via torus breakdown observed in a simple four-dimensional autonomous circuit including two diodes is investigated rigorously. This degenerate technique is uniquely comparable to the well-known slow-fast singular perturbation method. The idealized case where the diodes are assumed to operate as switches is considered. In this case, the governing equation is represented by a constrained equation, and the Poincaré mapping is derived rigorously as the circle map. The torus breakdown in the four-dimensional autonomous circuit is well explained by the Poincaré mapping. The theoretical results are verified by laboratory experiment.     

宽带高抑制性能电磁脉冲防护电路设计与实验

强电磁脉冲易通过天线、孔缝、线缆等多种耦合途径进入电子系统内部,造成敏感电子设备出现短暂故障或永久损毁。安装电磁脉冲防护电路可有效提高电子设备抗强电磁脉冲能力。基于LC选频网络和瞬态电压抑制(TVS)二极管,设计了一种宽带高抑制性能电磁脉冲防护电路,防护电路工作带宽超过2 GHz、插入损耗低于0.6 dB。系统性研究了防护电路对频谱分布在工作带宽内多种电磁脉冲(方波脉冲、宽带高功率微波、窄带高功率微波)的防护能力。结果表明:防护电路对不同类型电磁脉冲电压抑制比大于40 dB、耐受功率超过387 kW、而响应时间仅0.7 ns。该防护电路具有工作频带宽、电磁抑制性能好、响应速度快、耐受功率高等特点,对电子信息系统电磁防护加固具有重要意义。     

非线性二极管系统构成的不可逆热机性能特征分析

研究了一个非线性二极管系统构成的不可逆热机的性能,它是由分别处于两个温度不同的热库中,完全相同的两个非线性二极管反向连接后并联上一个电容器组成的.运用非线性系统涨落理论计算出从两个热库中吸收的热流,考虑热漏损失后得出热机的功率和效率.通过数值模拟可以绘出热机的性能特征曲线以及优化性能参数随两热库温度比等主要参量的特征曲线.分析了二极管的非线性强度、热漏损失和温度比对热机性能特性的影响.最后,讨论了理想二极管热机的性能特征.     

A five port hybrid ring mixer design

The design, construction and measured experimental characteristics of a Ka-band balanced mixer based on microstrip technology, are presented. The mixer was realised using a configuration of a rat-race hybrid with five ports and two GaAs beam lead Schottky diodes. This type of balanced mixer is advantageous because it avoids via holes, airbridges and crossing transmission lines that deteriorate the performance of the circuit, and make its construction more difficult. The circuit was constructed in uniplanar microstrip configuration, so the circuits pattern was defined on one side of the substrate only, using thin film techniques. Performance characteristics of the mixer are presented as a function of RF and LO power, RF frequency and voltage bias of the Schottky diodes.     

Ku波段编码式电控超薄周期单元设计与验证

编码式电控周期单元通过加载电子控制器件使周期结构具有编码式的电可调特点. 本文利用PIN二极管, 设计实现了一种工作在Ku波段的超薄平面电控单元结构. 当外加电压控制二极管导通或截止时, 该结构的反射相位呈现出180°的相位差, 并且具有较低的反射损耗. 因此, 当对周期排列的单元外加不同的电压时, 可等效为用不同组合的“1”, “0”对结构进行编码, 从而可以获得不同的电磁功能. 为验证单元的编码特性, 从“场”与“路”两个角度考虑, 设计了实际的偏置电路, 制作了单元样品, 并基于波导法测试了其性能. 实验结果表明: 在加载不同的控制电压时, 制作的单元结构实现了设计的低损耗和相位差; 实验与仿真符合良好. 提出的周期单元形式简单, 厚度超薄, 其电控编码式特性在主动式隐身表面或波束捷变天线设计等许多方面都有潜在应用.     

基于VXI总线的四路门控积分器模件的研制

 介绍了一个基于标准总线VXI的四路门控积分器模块插件。在四路独立的纳秒门控积分电路的基础上,采用VXI寄存器基接口实现对各路门控积分器的数据采集和控制,采用Labwindows/CVI编写了数据采集系统软件,从而完成了纳秒级门控积分器的实用化的基本工作。电子学测试结果和现场打靶结果表明该系统完全符合实用系统的要求。     

聚合物电致发光器件工作层热效应的喇曼光谱研究

以喇曼光谱和红外测温仪为表征手段, 研究了聚合物电致发光器件在施加不同电流密度的工作条件下器件内部热效应对器件老化的影响. 通过实验得到器件内发光层的斯托克斯喇曼信号和反斯托克斯喇曼信号强度的比值, 代入波尔兹曼方程计算得到该层对应的温度, 从而达到精确测量器件内部工作温度的目的. 通过对器件施加0~169 mA/cm²的电流密度, 发现器件内部工作温度逐渐升高, 最终达到有机层的玻璃化转变温度后, 发光层材料发生相变, 变成游离状的液态, 这种状态不稳定, 造成发光层材料的局部缺陷, 使得器件阴阳极短接导致器件短路, 从而发光失败. 实验表明喇曼光谱是一种探测薄膜器件内部工作层温度的有效手段.     

Development of an extremely wide-band planar frequency doubler from Q-band to W-band

A very broadband Q- to W-band MIC frequency doubler with a 28-GHZ band-width, employing a unique planar balanced circuit configuration, has been developed with good performance. Using two beamlead Schottky barrier diodes as varistors, the doubler exhibits an output power of 7±1 dbm and conversion loss of 13±1 db over the 66 to 94 GHZ output frequency range. The development demonstrates a unique concept in realizing wideband planar millimeter wave solid-state sources.     

GaN发光二极管表观电容极值分析

利用正向交流(ac)小信号方法对GaN发光二极管的电容-电压特性进行测量,可以观察到GaN发光二极管中的负电容现象。正向偏压越大,测试频率越低,负电容现象越明显。测量到的负电容现象是表象,不存在负电容;提出GaN发光二极管p-n结的结电容在特定的正向电压范围内等效于可变电容。分析可变电容对正向交流小信号响应得到:特定参数的可变电容使结电容电流相位落后于交流小信号电压相位π/2,使得在测量中表现为负电容。发现表观电容-正向电压曲线的极值点与理论模型相吻合,证明了该理论模型的正确性。     

阻尼作用下振子相图的电路模拟

电学量和力学量之间存在一一对应的关系,例如弹簧振子振动和LC电路的微分方程具有相同的形式.我们用电路系统在示波器中直接展现出电磁振荡过程,模拟了黏滞阻尼振动过程的相图.又利用稳压二极管模拟了摩擦阻力作用下弹簧振子振动的相图.将一道力学问题找到对应的电路模拟,在教学过程中具有启发意义.     

Modified Maxwell–Wagner model analysis on charging and discharging in TIPS-pentacene diode by optical second harmonic generation measurement

We used time-resolved electric field induced optical second harmonic generation (TR-EFISHG) measurement and Maxwell–Wagner (MW) equivalent circuit model analysis to study the charging and discharging processes of ITO/Polyimide/6,13-Bis(triisopropylsilylethynyl)-pentacene/Au (ITO/PI/TIPS-pentacene/Au) diodes. For fresh diodes, electrode charging was followed successively by interfacial charging, whereas interfacial discharging occurred very quickly in combination with electrode discharging. In contrast, the order of charging and discharging was reversed for aged diodes. A modified MW equivalent circuit well accounts for these results, where TIPS-pentacene functions as a dielectric material before hole injection, but as a conductor after hole injection. As a result, the accumulated interfacial charge can escape very quickly from the TIPS-pentacene together with electrode discharging. These results illustrate the non-reversal behavior of the fresh TIPS-pentacene diodes.     

隧道二极管伏安曲线二次微商与直流偏压关系的测量

本文提供测量隧道二极管伏安曲线二次微商与直流偏压关系的谐波分析法。着重讨论测量原理,电路设计和误差对结果的各种影响。同时,指出进行这项工作对隧道二极管应用和它的物理性质研究的意义。文中介绍了典型测量结果。并对隧道二极管作低电平检波器应用的价值作了一些定量的讨论。     

高功率激光装置中超快电脉冲发生器的研究

报导了一种基于雪崩晶体管和阶跃恢复二极管的超快前沿、低触发晃动方波电脉冲产生技术.利用雪崩晶体管的电触发雪崩导通特性得到脉冲主体,再用阶跃恢复二极管的超快阶跃恢复特性对脉冲前沿整形,从而得到输出脉冲幅度23 V、输出阻抗50Ω、脉冲前沿小于160 ps的方波脉冲,脉冲触发晃动小于4.5 ps(rms),脉冲宽度5 ns,幅度稳定性优于3%,顶部不平坦度优于5%.该脉冲发生器在“神光Ⅲ”高功率激光原型装置前端系统中获得成功应用.     

不同位置二极管串并联方式对射频电路的影响

分析了单支肖特基二极管以及串并联模拟预失真电路的幅度和相位的非线性特性,仿真结果表明可以将二极管作为模拟预失真电路可调节的核心器件。利用传输矩阵分析得出改变肖特基二极管在预失真电路的不同位置,及不同的串并联连接方式,可以使幅度相位补偿曲线得到改善。由仿真结果可以看出,在不同位置以串联或并联的形式在电路中连接二极管,可有效改变曲线的位置和斜率,从而得到理想的目标曲线形状。