An RF power amplifier with inter-metal-shuffled capacitor for inter-stage matching in a digital CMOS process

One challenge of the implementation of fully-integrated RF power amplifiers into a deep submicro digital CMOS process is that no capacitor is available, especially no high density capacitor. To address this problem, a twostage class-AB power amplifier with inter-stage matching realized by an inter-metal coupling capacitor is designed in a 180-nm digital CMOS process. This paper compares three structures of inter-metal coupling capacitors with metal-insulator-metal (MIM) capacitor regarding their capacitor density. Detailed simulations are carried out for the leakage, the voltage dependency, the temperature dependency, and the quality factor between an inter-metal shuffled (IMS) capacitor and an MIM capacitor. Finally, an IMS capacitor is chosen to perform the inter-stage matching.The techniques are validated via the design and implement of a two-stage class-AB RF power amplifier for an UHF RFID application. The PA occupies 370 X 200 μm2 without pads in the 180-nm digital CMOS process and outputs 21.1 dBm with 40% drain efficiency and 28.1 dB power gain at 915 MHz from a single 3.3 V power supply.     

基于多因素分析的微网综合效益评价

为评价含有风电、光伏发电及微型抽水蓄能发电的微网系统的效益,采用多因素分析方法,通过电力不足概率和期望缺供电量两个指数检验微网供电可靠性,采用净现值、效益费用及回收期三个度量指标评价微网系统经济性,并通过计算安装微网系统后减少的碳排放量评估微网环境效益,最终得到微网的综合效益评价结果。结果表明,微网系统拥有较高的经济和环境效益,且运用蓄电池技术可显著提高微网的可靠性。     

Programming Liquid Crystalline Elastomer Networks with Dynamic Covalent Bonds

A liquid crystalline elastomer (LCE) network consisting of dynamic covalent bonds (DCBs) is referred as a LCE vitrimer. The mesogen alignment and the network topology can be reprogrammed locally in the LCE vitrimer by activating the bond exchange reactions using an external stimulus. After removal of the external stress, a new network is formed and the reprogrammed shape can be fixed, leading to a different set of the physical properties of the LCE vitrimers. Herein, this type of emerging materials is reviewed by a brief introduction of the fundamentals of LCEs, followed by discussions of various DCBs and the design principles for LCE vitrimers. After a presentation of different strategies to improve the stability and reprogrammability of the registered mesogen alignment, approaches to prepare LCE vitrimers with complex shapes and their actuations are discussed. Potential applications such as self-healing and recycling, mechanochromic effects, and post-functionalization of nanopores are also reviewed, followed by the conclusion of the remaining challenges and opportunities.     

高动态下GPS信号的捕获和跟踪技术研究

为检测高动态GPS信号,需要设计码环及载波环的捕获和跟踪数字系统。如何快速捕获信号,并进行精确跟踪,是问题的关键。针对高动态环境下GPS信号的捕获和跟踪问题,分析了高动态环境对GPS信号的影响,提出了FFT码快速捕获算法,以及二阶FLL与三阶PLL混合载波跟踪方案,并对码环和载波环的结构和参数的设计方法进行了说明。仿真结果和分析表明该方案能在高动态环境下实现信号的快速捕获,且能较好地满足接收机动态性能和跟踪精度的要求。     

基于自动微分技术的器件模型参数提取算法

自动微分 (AD)技术以非标准分析为理论基础 ,是计算机数值计算领域中的一种很有前途的方法。文中提出了基于 AD技术的器件模型参数提取算法 ,在 Visual C+ +平台编制了模型参数提取程序 ,对所建立的基于表面势的 MOSFET模型进行了有约束条件的参数提取。结果表明 ,算法收敛快、稳定性好、提取准确     

随钻测量电磁信道分析的等效传输线法

等效传输线法用于随钻测量电磁传输信道的分析，在当前仍然是一种比较有成效的方法。本文对现有近似法中所采用的等效传输线模型作了一些改进，使之在物理图象上更为确切，并能够对井下激励装置有关参数的影响进行估计。     

基于机器视觉的纺织样品图像动态范围扩展方法研究

针对目前机器视觉采集纺织样品的图像动态范围低,严重影响对其质量的分析效果,提出一种通过多帧图像融合来改善图像质量的方法.采用对同一视场多帧不同曝光图像加权平均得到融合图像.并在融合算法中,引入数学多元统计主成份分析方法,估计不同光强条件下获取图像的权重.在处理过程中,对协方差矩阵估计权值的方法进行了改进,克服只能对一个...     

从废钒催化剂中回收钒氧化物的研究

研究了将废钒催化剂经过氧化焙烧、水浸、渣碱浸、离子交换等工序制备偏钒酸铵或五氧化二钒的新工艺.探讨了工艺参数对附加剂配方、氧化焙烧、浸钒、离子交换及偏钒酸铵沉淀影响的规律性,为推广工业生产提供适宜的工艺条件.在此工艺条件下,可以制备出质量优于GB/T 3283-1987冶金99级标准的五氧化二钒产品,具有较好的经济效益和社会效益,市场前景广阔.     

离子交换法回收废钒催化剂中钒的研究

研究了采用离子交换法回收废钒催化剂中钒的新工艺，并着重对浸钒、沉钒等环节进行了改进。探讨了回收废钒催化剂过程中，离子交换树脂、钒溶液浓度、流速、温度、淋洗剂和沉钒溶液的pH、温度、加氨系数等因素对钒回收率的影响，得出了适宜的工艺条件。在此工艺条件下，可以制备出质量优于GB3283-1987冶金99级标准的五氧化二钒产品，钒回收率达91，7％，具有较好的经济效益和社会效益，市场前景广阔。     

基于多馈入交互作用因子的直流分区原则和方法研究

运用VSC-HVDC对多直流馈入系统进行分区能够提升受端系统的运行性能。不同分区方案对系统性能提升程度不同。为了寻找最优方案,运用灵敏度分析法对多直流馈入系统的特性进行了研究,得到了制定分区方案的两个基本原则。在此基础上提出了基于多馈入交互作用因子的直流分区方法,进而得到受端系统分区的最优方案。以广东电网2030水平年作为案例,运用该分区方法对广东电网进行分区,得到了最优分区方案。运用PSS/E 进行仿真,验证了该最优分区方案的有效性。该方案对于实际工程中分区方案的制定具有指导意义。