“In‐field” cell temperature evaluation in solar modules through time‐dependent open circuit voltage measurements

A method for the evaluation of p–n junction cell temperature in PV modules operating in the maximum power point (MPP) mode has been proposed. The method does not require specialized equipment and (for the concentrator modules) the data on the open circuit (OC) voltage temperature coefficients measured under pulse illumination. It consists of measuring several open circuit voltage magnitudes together with temperature measurements on the external module surface near one of the cells. In this procedure, a fast transition from MPP to OC operational mode is carried out, during which a time‐dependent voltage measurement is carried out with the help of a memory oscilloscope. A “reference” OC voltage magnitude in a “cold” module (a condition, as if the cells are kept at ambient temperature) is obtained by calculations, so that there is no necessity in a fast mechanical shuttering of the module aperture area. In the case of the concentrator modules, the module OC voltage temperature coefficient can be measured, if heat sinking process is artificially modified during outdoor measurements. Copyright © 2015 John Wiley & Sons, Ltd.     

Hybrid Linear Closed‐Form Solution in Wireless Localization

In wireless localization, several linear closed‐form solution (LCS) methods have been investigated as a direct result of the drawbacks that plague the existing iterative methods, such as the local minimum problem and heavy computational burden. Among the known LCS methods, both the direct solution method and the difference of squared range measurements method are considered in this paper. These LCS methods do not have any of the aforementioned problems that occur in the existing iterative methods. However, each LCS method does have its own individual error property. In this paper, a hybrid LCS method is presented to reduce these errors. The hybrid LCS method integrates the two aforementioned LCS methods by using two check points that give important information on the probability of occurrence of each LCS's individual error. The results of several Monte Carlo simulations show that the proposed method has a good performance. The solutions provided by the proposed method are accurate and reliable. The solutions do not have serious errors such as those that occur in the conventional standalone LCS and iterative methods.     

Magneto-transport characterization using quantitative mobility-spectrum analysis

A quantitative mobility spectrum analysis (QMSA) of experimental Hall and resistivity data as a function of magnetic field is presented. This technique enables the conductivity contribution of bulk majority carriers to be separated from that of other species such as thermally generated minority carriers, electrons, and holes populating n and p doped regions, respectively, and two-dimensional species at surfaces and interface layers. Starting with a suitable first trial function such as the Beck and Anderson mobility spectrum analysis (MSA), a variation on the iterative procedure of Dziuba and Gorska is used to obtain a mobility spectrum which enables the various carrier species present in the sample to be identified. The QMSA algorithm combines the fully automated execution and visually meaningful output format of MSA with the quantitative accuracy of the conventional least-squares multi-carrier fitting procedure. Examples of applications to HgCdTe infrared detector materials and InAs/GaSb quantum wells are discussed. The ultimate goal of this paper is to provide an automated, universal algorithm which may be used routinely in the analysis and interpretation of magneto-transport data for diverse semiconductor materials and bandgap engineered structures.     

SnAgCu体钎料及BGA焊球焊点纳米级力学性能

为了研究低银Sn-0.3Ag-0.7Cu无铅体钎料、BGA焊料小球和BGA焊点的力学行为,基于物理反分析的方法采用纳米压痕仪对其进行实验。从压痕载荷–深度曲线提取出弹性模量、硬度和蠕变速率敏感指数。结果表明:体钎料的杨氏模量和蠕变速率敏感指数大约是BGA焊料小球和BGA焊点的2.5倍,验证了尺寸效应理论。采用纳米压痕仪测出的体钎料维氏硬度(15.101HV)小于显微硬度计的测量结果(20.660HV)。     

Behaviour of CPW and TFMS lines at high temperature for RF applications in sub-45 nm nodes

Coplanar waveguide (CPW) and thin film microstrip (TFMS) lines integrating porous ultra low-k as inter-metal dielectric layers (k = 2.5) and copper as metal, are for the first time experimentally measured up to 110 GHz and under different temperature conditions, up to 200 °C. The extracted attenuation and propagation coefficients of those transmission lines are compared to simulations performed with MAGWEL software, a frequency domain 3-D Maxwell solver. Based on the characterization results some guidelines related to interconnect design are presented for future applications.     

集中式BLUE滤波器在组网雷达中的应用

为解决组网雷达对目标跟踪中的量测非线性问题,提出基于最佳线性无偏估计器(BLUE)准则的融合滤波方法。建立以融合中心为原点的组网雷达对目标定位的量测方程,推导出极坐标系与球坐标系下跟踪目标的BLUE滤波模型。理论分析表明,集中式BLUE滤波架构在估计单个雷达量测转换误差统计特性的同时,还估计出雷达间量测转换误差的统计特性。因此,跟踪精度和置信度较分布式BLUE滤波方法有显著提高,计算量较其他算法也有明显优势。不同场景下的仿真分析证明:该方法在不同状态噪声水平下的表现优异,是一种很有竞争力的跟踪算法。     

New single-stage low dc bus voltage stress converter for universal line applications

A new single-stage power factor corrected ac–dc converter for universal line applications is proposed in this paper. This converter has a buck topology as a power factor corrector. The dc bus voltage of the proposed converter is always lower than the peak input voltage at any load condition. Therefore, the problem of high dc bus voltage under the light load condition for the single-stage converter is solved, especially in the case of universal line applications. The design equations are presented for the proposed converter and a design example for a 5V 12A application is presented. The theoretical analysis and experimental results show that the dc bus voltage can be limited within 260V and the line input current harmonics can meet IEC 61000-3-2 Class D requirements at any load conditions for the line input voltages from 90 to 260V_ac.     

Testing the effects of temperature and humidity on printed passive UHF RFID tags on paper substrate

This article is an interesting substrate material for environmental-friendly printable electronics. In this study, screen-printed RFID tags on paper substrate are examined. Their reliability was tested with low temperature, high temperature, slow temperature cycling, high temperature and high humidity and water dipping test. Environmental stresses affect the tag antenna impedance, losses and radiation characteristics due to their impact on the ink film and paper substrate. Low temperature, temperature cycling and high humidity did not have a radical effect on the measured parameters: threshold power, backscattered signal power or read range of the tags. However, the frequency response and the losses of the tags were slightly affected. Exposure to high temperature was found to even improve the tag performance due to the positive effect of high temperature on the ink film. The combined high humidity and high temperature had the most severe effect on the tag performance. The threshold power increased, backscattered power decreased and the read range was shortened. On the whole, the results showed that field use of these tags in high, low and changing temperature conditions and high humidity conditions is possible. Use of these tags in combined high-humidity and high-temperature conditions should be carefully considered.     

An Adaptive Time Delay Estimator Based on ETDE Algorithm with Noisy Measurements

We address the problem of adaptive time delay estimation with noisy measurements. We develop a computationally efficient adaptive time delay estimator based on Explicit time delay estimation (ETDE) algorithm, by applying the unbiased impulse response estimation ap-proach. In this algorithm, a weighted error function is de-rived, and the time delay is explicitly parameterized in the filter coefficients and iteratively updated directly by uti-lizing the modified error function. Simulations validate the performance of the proposed algorithm for colored input and low signal-to-noise ratio scenarios.