一种Ka频段瓦片式TR组件子阵集成方案

提出了一种Ka频段瓦片式TR组件子阵集成方案,采用多层电路技 术、内层带状线功分器、优化脊波导口径、同型端口集中分布等手段大幅提高集成度,采用 高可靠性小截面脊波导实现模块间高性能垂直互联。给出了TR组件子阵电路布局设计,对小 截面脊波导传输特性、脊波导-微带探针过渡和集成功率分配网络等关键无源电路进行了设 计、仿真和测试。测试结果表明其性能和尺寸满足Ka频段TR组件子阵集成要求。     

多基地空时码探测信号设计及时反相关检测技术

为实现浅海复杂环境下的多基地声纳多源目标回波分辨,本文设计了一种适用于多入多出垂直阵信道环境下的空时码探测信号,并针对倾斜垂直阵的多途子信道差异问题,提出了信号的时反相关检测技术.空时码探测信号采用伪随机信号调制,具有良好的正交性,能在抗子信道严重衰落的同时,分辨多源目标回波.垂直阵受水流冲击,呈倾斜状态时,其多途子信道不一致性会导致各子信道传递信号无法在接收端聚焦,使阵列增益受损,同时导致时延测量能力下降和信号判决错误率上升,为此本文设计了信道训练信号用以估计多途子信道环境,通过虚拟时间反转镜获得子信道不一致条件下的最佳匹配检测信号,实现对接收信号的时反相关检测.仿真结果表明,本文所设计的探测信号和检测方法,能够克服复杂的信道条件和多途子信道不一致性引起的检测问题,满足多基地声纳探测需求,实现多源目标回波分辨.     

Reaction mechanism and products of the thermal conversion of hydroxy-containing polyimides

Thermal treatments of hydroxyl-containing polyimide materials at high temperatures are believed to lead to unique structural and chemical changes to the polymer backbone and side groups. These rearrangements when applied to specific polymeric membranes improve both their permeability and selectivity over conventional materials and this development has been attributed to the formation of nanoporous cavities in the treated products. However, the mechanisms of the possible chemical reactions that take place and the structures of the end-products have been poorly understood. With validated evidence from experiments and virtual screening of different precursors and possible products by molecular simulation, we have determined that hydroxy-containing polyimides can be thermally rearranged into poly(biphenylene bisimide) polymers under designed conditions. The proposed reaction mechanism is novel and calls into question the previously reported polybenzoxazole mechanism of thermal rearrangement. The new results indicate that the exact conditions of synthesis and thermal treatment of the starting polyimides will be critical to the properties of the membranes produced.     

降低光OFDM系统峰均比的TR-clipping算法

针对光正交频分复用(O-OFDM)系统中峰值平均功率比(PAPR)过高的问题,对传统的预留子载波(TR)方法进行了改进并引入到O-OFDM系统,提出将削波与TR法相结合,以减小削波噪声对信号的影响,同时有效降低信号的PAPR。研究结果表明:本文方法计算复杂度较低,易于实现;通过合理地选取门限A与预留子载波条数W的大小,可以有效抑制削波噪声在信号带内与带外引起的畸变;在误码率BER=10-6的条件下,当削波率γ由7dB降低至2dB时,所需的光信噪比(OSNR)相比削波法降低了0.2～7dB。     

Kinetic Analysis of a Two‐Phase EC Mechanism with Concomitant Lateral Processes

Electrochemical transfer of azo dye fast red TR across the water/1,2 – dichloroethane (DCE) interface followed by the coupling reaction with 1‐naphthylamine in the organic phase is studied. Pseudo first order rate constants of this reaction were obtained by fitting the experimental I_p?/I_p+ ratio under different experimental conditions with the theoretical values reported by Nicholson and Shain. The occurrence of lateral processes is demonstrated (partition of the azo dye non assisted by potential and electrochemical transfer of the protons generated in the coupling reaction), which constrains the accurate determination of the kinetic parameters.     

结构功能一体化相控阵天线高密度集成设计方法

提出了一种新的结构功能一体化相控阵天线的高密度集成设计方法。采用低温共烧陶瓷(LTCC)技术实现了有源相控阵天线的一体化设计,包括天线阵面、瓦式收发(TR)组件、热控装置、馈电网络的高密度集成。采用ANSYS等软件对天线的系统体系构架、总体性能评估、共形承载天线罩、天线阵面、瓦式TR组件以及系统热设计进行仿真分析并进行实物加工和测试。结果表明,该天线的等效全向辐射功率(EIRP)为23.6 dBw,噪声为3.57 dB,测试值与设计值吻合很好。     

一种基于LXI总线的TR组件S参数自动测试系统的设计

针对有源相控阵雷达天线中TR组件S参数测试工作量大、控制信号繁琐且测试结果需要大量分析处理的特点,设计了一种基于LXI总线的TR组件S参数自动测试系统。重点阐述了单次校准多次测量技术、开关矩阵设计、LXI总线仪表通讯等关键技术。该测试系统具有快速高效、可靠性高、使用方便灵活的特点,能够满足TR组件的测试要求。     

Time-resolved SAXS measurements facilitated by online HPLC buffer exchange

Small‐angle X‐ray scattering (SAXS) is a powerful technique to structurally characterize biological macromolecules in solution. Heterogeneous solutions are inherently challenging to study. However, since SAXS data from ideal solutions are additive, with careful computational analysis it may be possible to separate contributions from individual species present in solution. Hence, time‐resolved SAXS (TR‐SAXS) data of processes in development can be analyzed. Many reported TR‐SAXS results are initialized by a sudden change in buffer conditions facilitated by rapid mixing combined with either continuous or stopped flow. In this paper a method for obtaining TR‐SAXS data from systems where the reaction is triggered by removal of a species is presented. This method is based on fast buffer exchange over a short desalting column facilitated by an online HPLC (high‐performance liquid chromatography) connected to the SAXS sample cell. The sample is stopped in the sample cell and the evolving reaction is followed. In this specific system the removal of phenol initiates a self‐association process of long‐acting insulin analogues. For this experiment, data were collected in time series while varying concentrations. The method can be generally applied to other systems where removal of a species or other changes in experimental conditions trigger a process.     

采用TR069协议实现机顶盒的管理功能

首先阐述了家庭网络设备的特点,提出家庭网络设备远程管理需要解决的技术问题主要集中在管理通道和管理协议两方面,对于管理协议主要权衡内容包括功能、安全性和实现难度,并对目前两种主要的管理协议SNMP和TR069在功能、安全性和实现难度等方面进行了比较,提出TR069协议,可以更好的解决家庭网络设备远程管理的技术难题.在此基础上,简单介绍了TR069协议的主要内容及其STB数据模型,进而详细阐述了如何采用STB数据模型来实现机顶盒的配置管理、性能管理和故障管理等功能.     

基于开源硬件的TR组件原位检测设备设计

基于相控阵雷达TR组件原位快速检测的需求,介绍了一种能快速实现的外场原位检测设备研制方法。通过分析被测对象的工作原理和输入输出接口,介绍了检测设备的测试功能,给出了如何利用开源模块来实现专用测试设备的设计方案、系统框图和软件流程图。实际测试表明：该检测设备能够满足TR组件的原位检测要求,具有便携、故障定位准确、开发周期短等优点。