17.9% Metal‐wrap‐through mc‐Si cells resulting in module efficiency of 17.0%

We obtained 17.9% cell efficiency on thin and large mc‐Si REC wafers using ECN's metal‐wrap‐through (MWT) concept. Optimization of several cell processing steps led to an increase of more than 2% absolute in cell efficiency. With these cells 36‐cell modules were manufactured at 100% yield in our industry scale module pilot line. The highest module efficiency obtained (as independently confirmed by JRC‐ESTI) was 17%. In this module the average cell efficiency was 17.8%; this shows a small difference between cell and module efficiency. Copyright © 2011 John Wiley & Sons, Ltd.     

高温AlN为模板的AlGaN基p-i-n背照式日光盲探测器

第一次报道了以高温AlN为模板层的AlGaN基p-i-n背照式日光盲探测器的制作和器件特性.利用MOCVD方法在(0001)面的蓝宝石衬底上生长了探测器的AlxGa1-xN多层外延材料.在无需核化层的高温AlN模板上生长了p-i-n背照式日光盲探测器的无裂纹高Al组分(0.7)AlGaN多层外延结构.利用在线反射监测仪、三轴X射线衍射及原子力显微镜表征了外延材料的晶体质量.在1.8V的反向偏压下,制作的探测器表现出了日光盲响应特性,在270nm处最大响应度为0.0864A/W.具有约3.5V的正向开启电压,大于20V的反向击穿电压,在2V的反向偏压下暗电流小于20pA.     

一种研究不均匀介质中激光传输的新方法

为了解决非均匀介质中的光传输问题,利用光学相位共轭波的时间反演特性,实现了对克斯林衍射积分公式的改进.并通过改进后的计算方法对均匀及非均匀介质中的光传输进行了数值模拟.模拟结果表明,该方法能够实现计算非均匀介质中的衍射场的近场分布的计算.这一结果对高功率激光系统中的传输模拟和参数优化等问题是有帮助的.     

基于次优匹配处理的分布式目标检测

从最佳匹配滤波理论和主分量分析理论出发,推导出一种基于次优匹配处理方案的雷达分布式目标恒虚警率检测方法。实测数据仿真的结果表明:与能量积累检测和双门限检测法相比,次优匹配检测方法有较好的检测性能。     

一种均匀圆阵幅相及互耦误差校正算法

阵元幅相、互耦误差对阵列DOA估计性能产生了严重影响。文章结合误差模型,提出了一种结合校正矩阵特殊结构设定约束条件的误差校正算法,进行的约束设定能够有效避免重复的无益估计过程,减少了运算复杂度,方法简便、快捷,且无需知道辅助源的精确位置信息便能够精确估计出误差参数及来波方位,最后通过仿真试验说明了算法的有效性。     

C 波段双极化低旁瓣阵列天线

本文设计制作了一种高隔离度低副瓣双极化平板阵列天线,该阵列天线采用角锥喇叭作为辐射单元,以获得 高增益,馈电网络采用空气带状线,以获得较低的馈电损耗,利用探针对喇叭馈电,可获得较高的极化隔离度。在阵 列设计中,采用泰勒加权算法以获得-23dB 的旁瓣,同时利用反相馈电技术使阵列的交叉极化小于-30dB。仿真和实 测结果表明,在6GHz±200MHz 内,驻波小于2,天线增益大于23dB,交叉极化电平小于-30dB.     

Performance analysis of dual-hop fixed-gain AF relaying systems with OSTBC over Nakagami-m fading channels

In this paper, we present outage probability and symbol error rate (SER) performance analyses of a dual-hop transmission using fixed-gain amplify-and-forward relaying in flat Nakagami-m fading channels. The system under consideration is equipped with multiple antennas at source and destination adopting orthogonal space-time block coding to provide transmit diversity and maximum ratio combining to provide receive diversity, respectively. For integer and half-integer m values, closed forms of exact outage probability and moment generating function (MGF) expressions are derived through cumulative distribution function (CDF) of the overall system signal-to-noise ratio. Closed-form exact SER expressions based on the overall CDF are obtained for binary phase shift keying, binary frequency shift keying and M-ary pulse amplitude modulation. Exact SER expressions based on the MGF method are also obtained for binary differential phase shift keying, M-ary phase shift keying and M-ary quadrature amplitude modulation. Moreover, the asymptotic diversity order analysis is performed through derivations of asymptotic outage probability and SER. Theoretical analyses are validated by Monte Carlo simulations showing perfect match between each other.     

A 500-600 MHz GaN power amplifier with RC-LC stability network

A 500-600 MHz high-efficiency, high-power GaN power amplifier is designed and realized on the basis of the push-pull structure. The RC-LC stability network is proposed and applied to the power amplifier circuit for the first time. The RC-LC stability network can significantly reduce the high gain out the band, which eliminates the instability of the power amplifier circuit. The developed power amplifier exhibits 58.5 dBm (700 W) output power with a 17 dB gain and 85% PAE at 500-600 MHz, 300 μs, 20% duty cycle. It has the highest PAE in P-band among the products at home and abroad.     

电磁冲击波发生器箔片多物理场设计优化

为实现高功率电磁冲击波发生器箔片的优化设计,利用多物理场仿真工具COMSOL Multiphysics 对箔片建模并进行仿真和优化。相较于高阶本征频率,箔片在一阶本征频率下振动时具有更大的振幅;提出了箔片形变收益最大点的概念,据此可分析箔片在不同激励下的转换效率并用于确定激励电路参数以实现高效输出;其后对3种不同结构的箔片的性能在仿真分析的基础上进行了比较讨论,得到了波纹结构箔片在同等激励下具有更大振幅的结论。论文工作对高效高功率电磁冲击波发生器的研制具有一定参考价值。     

高精度频差测量方法研究

针对分布式多基地雷达多源信号产生与处理技术的关键问题,分析了现有频差测试方法,探索高精度频差测量方案。通过频差扩展方法,完成被测源间相对频差指标的高精度测量系统方案设计。此方案克服了传统时间同步设备需要大量时间来校正频率误差的缺陷,使校正之后的精度大大提高。根据设计方案研制了试验样机和测试系统,并通过对高精度源间相对频差的测量获得实测数据,测试结果验证了高精度频差测量方案的可行性。