金属/介质/金属光栅结构强化吸收特性

本文从电磁场理论出发,研究了单层光栅的金属/介质/金属结构的共振,利用严格耦合波方法计算了金属/介质/金属光栅结构表面的光谱特性,利用金属/介质/金属膜层结构的色散关系和等效LC回路模型两种理论对金属/介质/金属光栅结构表面的共振现象进行研究,讨论了几何参数对金属/介质/金属光栅结构共振的影响,结果表明单层光栅的金属/介质/金属结构的共振由金属/介质界面上的表面等离子极化之间的耦合产生。     

Fabrication of rhenium Josephson junctions

Rhenium is a superconductor with a relatively weak tendency to oxidize, which is advantageous in superconducting quantum circuit and qubit applications. In this work, Re/A1-A1Ox/Re Josephson tunnel junctions were fabricated using a selective film-etching process similar to that developed in Nb trilayer technology. The Re films had a superconducting transition temperature of 4.8 K and a transition width of 0.2 K. The junctions were found to be highly reproducible using the fabrication process and their characteristics had good quality with a low leakage current and showed a superconducting gap of 0.55 meV.     

两种平衡电路——从经典到现代

研究两种平衡电路,它可以统一解释电位计、电桥和运放电路等各种零电路.用于运放以后,平衡电路可以克服经典应用时的局限性,特别是它能使平衡电路自动地、瞬时地达到平衡,并且能处理从直流扩展到包括低频、高频的交流信号.     

Bifurcation Control of Current-Mode Buck Converter via TDFC

Considering the TDFC controlled current-mode Buck converter featuring periodicity we propose a Fourier-decomposition based method for the bifurcation analysis of this system, hence the theoretical range of control gain of TDFC is determined. In addition, the power-stage experiment circuit is built and the control part is realized in a digital controller. The experimental results show that either bifurcation or chaos in the current-mode Buck converter can be controlled into the expectant period-1 orbit rapidly.     

电阻的测量方法研究

电阻的不同测量方法各有优点，其误差原因不同，数据处理方法也不一样．通过对电阻测定方法的研究，综合应用相关知识，加深对相关电路原理的认识和提高利用理论知识解决实际问题的能力．     

A New 3D Four-Wing Chaotic System with Cubic Nonlinearity and Its Circuit Implementation

A new 3D four-wing smooth autonomous chaotic system in which each equation contains a cubic product term is presented and physically implemented. Spectral analysis shows that the four-wing chaotic attractor has extremely wide frequency bandwidth compared with that of the Lorenz system and other four-wing chaotic systems, which is important in some relevant engineering applications such as secure communications.     

锁相环的相位模型与实验电路

讨论了锁相环的相位数学模型,给出了一种适合于数学的锁相环实验电路．     

高频地波雷达频谱监测系统的前端电路设计

利用超外差式接收和直接数字合成(DDS)技术设计了高频地波雷达频谱监测系统的前端电路．该电路能够根据雷达探测距离的远近选择相对应的噪声信号接收频段,为后续的数据采集与处理提供噪声电平数据．实验证明：本系统的跳频本振信号信噪比(SNR)优于60dB;对输入信号具有60dB左右的增益和1μV的灵敏度,满足了武汉大学研制的下一代高频地波海态监测雷达对频谱监测的需要．     

电流控阈技术及三值电流型 CMOS施密特电路

本文以开关信号理论为指导 ,对电流型 CM OS电路中如何实现阈值控制进行研究. 建立实现阈 值控制电路的电流传输开关运算 ,并用于指导电流型 CMOS施密特电路的开关级设计 .用 PSPICE程序 模拟证明了所设计的电路具有理想的施密特电路特性.     

T形网络与∏形网络的等效变换法

电阻的T形网络与∏形网络间的等效变换是电路计算中经常遇到的问题.一般教材都根据等效的概念采用基尔霍夫定律得到转换公式,过程复杂,不利于学生的理解和掌握.这里介绍一种更为简便易懂的推导方法.