分组增强型光传送网实现政企专线电路迁移

传统SDH/MSTP网络逐渐退网,10GE颗粒的DWDM网络逐渐被100GE颗粒的OTN网络取代,在此过程中,传统政企专线电路如何迁移是运营商关注的重点之一。本文以扬州电信分公司引入分组增强型OTN网络实施政企电路迁移及SDH/MSTP网络退网为例进行说明。

A Radial Stub Test Circuit for Microwave Power Devices

With the principles of microwave circuits and semiconductor device physics, two microwave power device test circuits combined with a test fixture are designed and simulated, whose properties are evaluated by a parameter network analyzer within the frequency range from 3 to 8GHz. The simulation and experimental results verify that the test circuit with a radial stub is better than that without. As an example, a C-band AlGaN/GaN HEMT microwave power device is tested with the designed circuit and fixture. With a 5.4GHz microwave input signal,the maximum gain is 8.75dB,and the maximum output power is 33.2dBm.

一种基于ASM-HEMT模型改进陷阱效应的GaN HEMT器件非线性模型

GaN高电子迁移率晶体管(HEMT)器件受制于陷阱效应,建立准确的非线性模型非常困难。介绍了表面势物理基高电子迁移率高级电路模型(ASM-HEMT),分析了标准ASM-HEMT模型在表征陷阱效应方面的不足,进而建立了新的陷阱模型电路拓扑及模型方程,新陷阱模型可以更好地表征器件陷阱俘获和释放电子的不对称性。基于0.25μm GaN HEMT器件,进行了脉冲I-V、多偏置S参数、负载牵引仿真及测试,并对新模型进行参数提取和建模。经过对比仿真和测试结果发现,新模型的仿真结果与实测结果比标准ASM-HEMT模型更加吻合,说明新模型表征陷阱效应更加准确,提升了模型的准确性,进而提高GaN HEMT功率放大器设计仿真的准确性。

Electrochemical migration behavior and mechanism of PCB-ImAg and PCB-HASL under adsorbed thin liquid films

The electrochemical migration（ECM） behavior and mechanism of immersion silver processing circuit board（PCB-ImAg）and hot air solder leveling circuit board（PCB-HASL） under the 0.1 mol/L Na2SO4 absorbed thin liquid films with different thicknesses were investigated using stereo microscopy and scanning electron microscopy（SEM）.Meanwhile,the corrosion tendency and kinetics rule of metal plates after bias application were analyzed with the aid of electrochemical impedance spectroscopy（EIS）and scanning Kelvin probe（SKP）.Results showed that under different humidity conditions,the amount of migrating corrosion products of silver for PCB-ImAg was limited,while on PCB-HASL both copper dendrites and precipitates such as sulfate and metal oxides of copper/tin were found under a high humidity condition（exceeding 85%）.SKP results indicated that the cathode plate of two kinds of PCB materials had a higher corrosion tendency after bias application.An ECM model involving multi-metal reactions was proposed and the differences of ECM behaviors for two kinds of PCB materials were compared.

Two-dimensional organic single-crystalline p-n junctions for ambipolar field transistors

Two-dimensional single-crystalline p-n junctions of organic semiconductors(pn-2 DCOSs) show great potential in organic logic circuits due to their single crystal nature and excellent ambipolar charge transport. However,there are only few reports on pn-2 DCOSs because it is difficult to obtain such highly ordered structure in p-n junction.Herein, a novel and effective solution processing method of secondary transfer technology based on the facile drop casting is used to fabricate devices of pn-2 DCOSs based on C8-BTBT(p-type) and TFT-CN(n-type) successfully. The high-performance ambipolar field transistors based on such ultrathin pn-2 DCOSs with several molecular layers thickness show wellbalanced ambipolar charge transport behaviors with hole mobility as high as 0.43 cm^2 V^-1 s^-1 and electron mobility up to 0.11 cm^2 V^-1 s(^-1), respectively. This work is essential for studying the intrinsic properties of organic p-n junctions and achieving high performance in organic complementary circuits.

Alloy-like ternary polymer solar cells with over 17.2% efficiency

Ternary strategy has been considered as an efficient method to achieve high performance polymer solar cells(PSCs). A power conversion efficiency(PCE) of 17.22% is achieved in the optimized ternary PSCs with10 wt% MF1 in acceptors. The over 8% PCE improvement by employing ternary strategy is attributed to the simultaneously increased JSCof 25.68 mA cm^-2, VOCof 0.853 V and FF of 78.61% compared with Y6 based binary PSCs. The good compatibility of MF1 and Y6 can be confirmed from Raman mapping, contact angle,cyclic voltammetry and morphology, which is the prerequisite to form alloy-like state. Electron mobility in ternary active layers strongly depends on MF1 content in acceptors due to the different lowest unoccupied molecular orbital(LUMO) levels of Y6 and MF1, which can well explain the wave-like varied FF of ternary PSCs. The third-party certified PCE of 16.8% should be one of the highest values for single bulk heterojunction PSCs. This work provides sufficient references for selecting materials to achieve efficient ternary PSCs.

A-D-A small molecule donors based on pyrene and diketopyrrolopyrrole for organic solar cells

Three new electron donating small molecules （SMs）, Pyr（EH-DPP）2, Pyr（HD-DPP）2 and PyrA（EH-DPP）2, are designed and synthesized through coupling electron rich pyrene core with electron deficient diketopyrrolopyrrole （DPP） terminals, of which the derived organic solar cells （OSCs） exhibit interesting structure-performance correlation. It shows that the tune of their solubilizing side chains and n-bridge for the acceptor-donor-acceptor （A-D-A） SMs can significantly alter the resultant short-circuit current density and power conversion efficiency （PCE） in OSCs. The Pyr（EH-DPP）2 with short side chains displays broader absorption and higher hole mobility than the Pyr（HD-DPP）2 with long side chains. Although showing planar structure, the acetylene bridge-incorporated PyrA（EH-DPP）2 adapts an undesired edge-on packing and strong aggregation in film, leading to non-ideal morphology and poor miscibility with fullerene acceptors. As a result, the PCE of the solar cell based on Pyr（EH-DPP）2 is several times higher than those based on Pyr（HD-DPP）： and PyrA（EH-DPP）2, indicating the A-D-A combination of polyaromatics with DPP would be the promising skeleton for developing photovoltaic semiconductors.