Effect of Al Composition and Gate Recess on Power Performance of AlGaN/GaN High-Electron Mobility Transistors

AlGaN/GaN high-electron mobility transistors with different Al compositions and barrier thicknesses were compared. The samples with higher Al composition and similar 2D electron gas density showed higher gate leakage, utilizing a slant field plate gate process. By applying a gate recess etch and a slant field plate gate process, gate leakage was improved to a similar level for all the devices, and the power density and PAE were much improved.     

二维信号Wigner分布的数值计算

Wigner分布函数作为一个同时表达空间 频率变量的函数 ,在光学领域中有着广泛的应用。提出了二维信号Wigner分布函数的数值计算方法 ,并模拟了一些二维实信号 (圆孔 ,圆环和方孔 )的Wigner分布函数     

网络连通性快速检测系统的实现

系统应用辅助CPU专一处理IEEE 802.1ag协议连通性检测消息报文的收发,实现了ms级的收发包,进行了链路的快速检测.采用两台设备模拟小型网络,验证了系统的功能及性能.     

Spontaneous Phase Separation of Poly(3‐hexylthiophene)s with Different Regioregularity for a Stretchable Semiconducting Film

Highly regioregular (RR) poly(3‐hexylthiophene)s PHTs are known to exhibit excellent electrical properties in comparison to chemically identical but regiorandom (rr) PHTs. In this study, distinct RR (97% and 55%)‐graded PHTs are subjected to solution blending to spontaneously separate the high‐RR PHT chains from the low‐RR PHT media and develop highly conjugated nanodomains in both solution and film. In the spun‐cast blend films, the rr PHT matrix imparts sufficient deformability of the channel layer required for stretchable organic thin‐film transistors (OTFTs), compared to neat RR PHTs and blends with a deformable polymer. OTFTs including RR PHT/rr PHT blend films show excellent hole mobility (µ) values up to 0.13 cm² V^?1 s^?1, surpassing that of the best RR PHT films (0.026 cm² V^?1 s^?1) fabricated by ultrasound solution pretreatment. Furthermore, a 50% stretched RR PHT/rr PHT film maintains ≈55% of its µ value at no strain, while RR PHT films show a sudden decrease in µ even at 10% stretch. The simple blending approach imparts deformability to π‐conjugated polymer films for application in stretchable OTFTs.     

基于FPGA的PCIe接口实现

PCI Express是一种高性能互连协议,被广泛应用于网络适配、图形加速器、网络存储、大数据传输以及嵌入式系统等领域。文中介绍了PCIe的体系结构,以及利用Altera Cyclone IV GX 系列FPGA实现PCIe接口所涉及的硬件板卡参数、应用层系统方案、DMA仲裁、PCIe硬核配置与读写时序等内容。     

High-capacity data hiding in halftone images using minimal-error bit searching and least-mean square filter.

In this paper, a high-capacity data hiding is proposed for embedding a large amount of information into halftone images. The embedded watermark can be distributed into several error-diffused images with the proposed minimal-error bit-searching technique (MEBS). The method can also be generalized to self-decoding mode with dot diffusion or color halftone images. From the experiments, the embedded capacity from 33% up to 50% and good quality results are achieved. Furthermore, the proposed MEBS method is also extended for robust watermarking against the degradation from printing-and-scanning and several kinds of distortions. Finally, a least-mean square-based halftoning is developed to produce an edge-enhanced halftone image, and the technique also cooperates with MEBS for all the applications described above, including high-capacity data hiding with secret sharing or self-decoding mode, as well as robust watermarking. The results prove much sharper than the error diffusion or dot diffusion methods.     

基于广义对数函数的统一路由策略

通过对最短路径路由策略、有效路由策略、最小信息路径路由策略的算法以及广义对数函数进行研究发现：将广义对数函数内的变量进行部分修改可实现以上三种算法的统一,并且通过对此种统一算法进行改进并且仿真发现,在此统一算法变量连续变化的同时,某些路由策略在复杂网络中的表现同样具有连续性。这表明此种算法可以将以上三种路由策略进行完美的统一。     

一种具有普适性的单子网物理拓扑发现算法

文中提出了一种适用于单子网异构IP网络的物理拓扑发现算法,此算法基于网络中的SNMP MIB库,具有普适性.在AFT信息不足的情况下,可用端口流量的关系获得端口的连接信息.理论和仿真证明,即使在有个别网络元素不支持SNMP的情况下,此算法仍可准确地进行物理拓扑发现.     

基于COB封装技术的100G SR4光模块设计

100GSR4光模块具有传输速率高、技术成熟和成本低等优势,已广泛应用于数据中心和数据通信接入网等领域.文中采用板上芯片封装(chip on board,COB)封装技术对100G SR4光模块电路、光路部分进行了开发设计,并采用自制测试系统对模块的发射接收性能进行了测试.测试结果表明,该模块完全符合协议的各项指标,可...     

由Web2．0看ICT的发展

面对互联网的强烈冲击,电信业务面临着网络能力、资源整合、产业链构建等“瓶颈”,亟需构建更具活力的机制。Web2.0应用互联网,是一个人与人之间的社会化网络,普遍为大家关心,但商业模式还不足十分清晰。可以学习借鉴互联网的发展思路来发展信息与通信技术（ICT）业务,同时通过IT电信化解决互联网业务的可运营、可管理、可维护问题,将互联网使用效果好、通业性强的业务应用于电信网,实现ICT业务融合。未来互联网将可能分为面向公众免费的互联网和用来运营的可信互联网,运营商将搭建更好的网络平台,将规模化的业务运营于可信互联网,使用户方便可靠地享受信息化服务。