宽带大功率限幅器小型化研究

采用微波混合集成电路设计方法,用并联二极管和检波二极管,在很小的腔体内制作了无源微波限幅器。其电参数为:频率范围2~18GHz;承受功率4W(连续波);限幅电平≤30mW(Pin为4W,连续波);插入损耗为2.5dB以下;驻波系数为2.0以下。外形尺寸为13.5mm×6mm×3mm;输入输出端为50?绝缘子。     

逻辑代数中反演定理和对偶定理的相互关系教学探讨

反演定理和对偶定理是逻辑代数中的重要定理,本文首先介绍了根据上述两个定理分别求逻辑式Y的Y'和YD的具体步骤,在此基础上,深入讨论了两个定理之间的相互关系。在教学过程中,对两个定理相互关系的探讨,促进了学生的理解,取得了良好的教学效果。     

应用ADA进行微带功分器的仿真设计

介绍微带功率分配器的基本设计理论和ADS的使用方法,并给出一个810-990MH二路功分器的计算机仿真验证步骤,仿真结果说明应用ADS进行设计有效性和可行性.     

电解液浓度对双槽法腐蚀多孔硅的影响

设计了一种电化学双槽腐蚀装置,研究了不同电解液的浓度对制备多孔硅形貌和光学特性的影响.研究结果表明采用此装置制备的多孔硅孔洞均匀性好,并且随NaCl电解液浓度的增加,制备的多孔硅孔径呈减小的趋势,发光强度有所增强.     

应用ADS进行微带功分器的仿真设计

介绍微带功率分配器的基本设计理论和ADS的使用方法,并给出一个810-990MH二路功分器的计算机仿真验证步骤,仿真结果说明应用ADS进行设计有效性和可行性.     

Electrospun zinc oxide nanospheres for ultrasensitive room-temperature gas sensors

Zinc oxide (ZnO) nanospheres with excellent sensing ability towards formaldehyde were successfully synthesized using a single-capillary electrospinning method. Structural and electrical characteristics of the as-synthesized ZnO nanospheres were systematically investigated. The scanning electron microscope (SEM) images clearly display a novel structure of ZnO with pores distributed on the surface of the nanospheres. The results demonstrate that the ZnO nanospheres possess excellent formaldehyde gas-sensing properties. At room temperature, the response of ZnO nanospheres to formaldehyde with concentration of 100 ppm is determined to be 126.3. In addition, the ZnO nanosphere sensors exhibit short response time of 30 s and short recovery time of 2 s. These excellent gas-sensing properties make the ZnO nanospheres a promising material for the application in environmental monitoring devices.     

基于STC89C58RD和SJA1000的CAN总线网关设计

为了使CAN总线的高可靠性、实时性和多主特性能在现场控制系统中得到充分应用,文中给出了能适应不同传输速率的CAN总线网关的设计方法。同时给出了采用STC89C58RD作为处理器．而用SJA1000作为CAN总线控制器来设计CAN网关的硬件设计结构软件设计过程。     

一种高g电容加速度计的设计

本文分析了电容式加速度传感器的工作原理,在此基础上设计了一种大量程加速度计,通过MATLAB进行系统仿真和ANSYS仿真验证,结果显示本设计可以很好的实现要求:量程70g,线性度小于2%,并有较好的稳定性。     

ISP在单片机实验教学中的应用

以前在单片机教学过程中,由于仿真器的价格比较高,编程器要不停地对单片机进行拔插,给调试带来不便,使一些实验无法让学生亲自动手,给单片机教学带来诸多不便,现在由于ISP技术的发展,克服了以上诸多不便,也给单片机教学和实验教学带来机遇。     

Nano-photonic crystal formation on highly-doped n-type silicon

We present a novel electrochemical technique for the fabrication of nano-photonic crystal structures. Based on a specially designed electrolyte, porous silicon(PSi) layers with different porosities are possible to be produced on highly-doped n-type silicon substrate by varying the applied current density which determines the size and the morphology of pores. By applying an alternative current density modulation during anodization, porous silicon photonic crystals are obtained using HF-containing electrolyte without oxidizing components. The current burst model(CBM) is employed to interpret the mechanism of the formation of the macropore porous silicon.