Design of high-repetition frequency gating circuit for cathode of image intensifier北大核心CSCD

According to the requirements of high repetition frequency, fast edge speed and small pulse width for cathode gating signal by range-gated technology, a cathode high repetition frequency gating circuit using period and multi-stage acceleration was proposed. By combining the RC circuit and the high-speed gate circuit, the time bias circuit unit was cascaded to generate logic pulses with different time sequences, which could respectively control the intermediate stage drive MOSFET to generate three phased drive signals, and the output of the intermediate stage drive was used as input of the output-stage MOSFET to control the acceleration and retention of its on-off process. It was verified by software simulation and board-level test. The test results show that the proposed gating circuit can increase the edge time of output pulse from μs level to 2 ns, and can provide +50 V/−200 V cathode off/on voltage, so as to achieve a repetition frequency ranging from 0~350 kHZ, a duty ratio of 0~100%, a minimum pulse width of 3.7 ns, and a pulse output delay time jitter of about 0.1 ns. It has important guiding significance for improving the minimum pulse width performance of high-speed and high-voltage gating power, the highest working repetition frequency and reducing the power loss of the device. © 2022 Editorial office of Journal of Applied Optics. All rights reserved.     

外接LC电路的可调压电换能器的频率特性

压电换能器往往因受到温度与负载的影响,导致其谐振频率、反谐振频率和机械品质因数等特征参数发生变化。通过在压电换能器中设计用于调节的压电陶瓷片,并在调节压电陶瓷片两端外接电负载,可以实现压电换能器的频率调节,修正由于温度和负载导致的频率漂移。基于压电换能器的Mason等效电路,建立外接LC调节电路的压电换能器的谐振频率、反谐振频率模型,分析LC调节电路中调节电感对频率调节特性的影响;通过实验研究外接LC调节电路对可调压电换能器机械品质因数的影响,并验证调节电感对频率调节特性的影响。理论分析和实验研究的结果表明:随着调节电感的增大,调节电容对频率的调节灵敏度提高,可调压电换能器的频率调节宽度拓宽,但也会使压电换能器的机械品质因数降低。合理选择调节电感和调节电容能兼顾频率调节宽度和机械品质因数的要求。此研究可为后续自适应压电换能器的频率调节系统设计提供指导。     

垂直腔面发射激光器的电路模拟

通过分析垂直腔面发射激光器的速率方程,并结合电子电路的特点,建立了等效电路模型。采用数值计算和电路模拟两种方法给出了垂直腔面发射激光器的频率响应特性。通过分析,证明了电路模型的正确性。通过电路模拟得出了脉冲调制的响应特性,验证了激光器固有的电光延迟和张驰振荡现象。     

一种具有恒Lyapunov指数谱的混沌系统及其电路仿真

提出了一种新的具有恒Lyapunov指数谱的三维混沌系统,该系统含有六个参数,其中一个方程含有一个非线性乘积项,一个方程含有平方项.通过理论推导、数值仿真、Lyapunov维数、Poincare截面图、Lyapunov指数谱和分岔图研究了系统的动力学特性,并分析了不同参数变化对系统动力学行为的影响,其中,平方项系统参数变化时,系统的Lyapunov指数谱保持恒定,输出信号中的两维信号的幅值与参数呈幂函数关系变化,其指数为－1/2,第三维信号的幅值保持在同样的数值区间.最后,设计了该混沌系统的硬件电路并运用Multisim软件对该电路进行仿真实验,证实了该混沌系统的可实现性. 关键词： 混沌系统 恒Lyapunov指数谱 Poincare截面图 混沌电路     

基于 MATLAB的RLC电路暂态过程的模拟

MATLAB以其强大的矩阵运算能力和简便的绘图功能,而成为理论研究和工程应用中流行最广的科学计算语言.简要介绍了MATLAB软件,再利用MATLAB对RLC暂态电路中的二阶微分方程进行了降阶处理,并对降阶后的微分方程进行了求解,最后还利用MATLAB的绘图功能,对电压的变化规律进行了模拟,模拟结果与实验结果相符.     

基于普通三极管电光调Q驱动器的实验研究

利用三极管的雪崩效应获得高电压、快速电光调Q脉冲存在雪崩效应不稳定、输出电压调节范围小、供电电压高等缺点。针对以上不足,采取在三极管基射极加电感使雪崩效应稳定,用高压场效应管替代两个三极管提高输出电压调节范围,利用MarxBank电路,降低供电电压。实验结果表明：电光调Q脉冲前沿2ns,幅度3500-6000V连续可调...     

高功率微波对PCB电路系统辐照效应的仿真分析

以实验室自主研发的2维半导体器件-电路联合仿真程序用于分析高功率微波注入下半导体器件的毁伤机理,以此2维半导体器件-电路联合仿真程序为基础加以扩展,添加了电磁波辐照射下微带线的SPICE电路模型。扩展后的程序可以同时用于分析平面波入射下含半导体器件的PCB电路的高功率微波辐照效应和置于带孔缝屏蔽腔中的PCB电路的高功率微波辐照效应。应用此仿真程序分析了一个含有低噪声放大器的简单PCB电路,得到了该PCB电路在不同形式平面波入射下低噪声放大器的烧毁阈值,在该PCB电路置于屏蔽腔中时,低噪声放大器输入端口出现耦合干扰电压情况。     

压缩真空态的激发态及其在非耗散介观含源电路的应用

借助逆算符的性质,提出了压缩真空态激发态的概念,作为应用,导出了非耗散介观含源电路在该激发态下其电荷和电流的量子零点涨落,数值计算表明,在不同的激发量子数下,电荷和电流均存在压缩效应,它们的不确定度之积分别趋向于一个最小值。     

Digital synthesis of programmable photonic integrated circuits

Programmable photonic waveguide meshes can be programmed into many different circuit topologies and thereby provide a variety of functions.Due to the complexity of the signal routing in a general mesh,a particular synthesis algorithm often only accounts for a specific function with a specific cell configuration.In this paper,we try to synthesize the programmable waveguide mesh to support multiple configurations with a more general digital signal processing platform.To show the feasibility of this technique,photonic waveguide meshes in different configurations(square,triangular and hexagonal meshes)are designed to realize optical signal interleaving with arbitrary duty cycles.The digital signal processing(DSP)approach offers an effective pathway for the establishment of a general design platform for the software-defined programmable photonic integrated circuits.The use of well-developed DSP techniques and algorithms establishes a link between optical and electrical signals and makes it convenient to realize the computer-aided design of optics–electronics hybrid systems.