Broadband bowtie belt nanoantennas

In this article, we study a linear array of bowtie nanoantennas placed between two metallic strips that can work from 800 to 1420 nm (600 nm linewidth), with an electric field enhancement factor close to 20. We study the dynamical change of the position of the electric field enhancement amongst different elements in the array and, at the same time, the effects of dispersion on the scalability of the array elements. A systematic analysis and methodology to produce an array that can operate over a large bandwidth whilst maintaining the electric field enhancement without significant variation is provided.     

MODIS数据Bowtie效应消除算法

MODIS数据不仅具有较高的过境频率和光谱分辨率,还具有成本低、覆盖面广等优势。受地球曲率的影响,MODIS L1B数据大多存在一种重叠效应,即Bowtie效应,主要发生在图像的边缘地带,该效应制约了MODIS遥感数据的进一步分析及应用。针对遥感影像几何畸变问题,提出一种不基于传统星历表的Bowtie效应消除算法,采用相关系数法确定每个扫描带的重复行数,根据不同分辨率的MODIS L1B数据,使用相对应的重采样方法对图像进行重采样处理。通过与其他Bowtie效应消除算法的对比实验及分析,证明该算法不仅能够有效去除Bowtie效应,而且执行速度较快,具有较高的工程应用价值。     

一种近似核线影像相关法在遥感图像处理中的应用*

MODIS遥感图像数据L1B产品中存在着Bowtie Effect,即“双眼皮”现象,几何纠正后仍无法去除,因此必须在几何纠正前加以去除。而目前大型商用图像处理软件如POTOSHOP及遥感处理软件ENVI,ERDAS等还没有现成的处理工具。提出一种近似的核线影像相关法和一个快速去除MODIS“双眼皮”的思路,实验证明效果很好。     

4-element planar array antenna for UWB application

A novel low-cost 4-element planar array antenna directly fed by a coaxial cable for Ultra-WideBand(UWB) application is presented. The proposed antenna consists of 2×2 bowtie elements and a simple 1:4 power divider feeding network. Compared to the basic bowtie element, the impedance bandwidth of the array antenna has a significant improvement that the low cut-off frequency is extended from 6 GHz of the bowtie element to 2 GHz. The measured results show that the proposed antenna has a large bandwidth of 2 GHz to 11 GHz for Voltage Standing Wave Ratio(VSWR)2, and exhibits a bidirectional radiation pattern and a modest gain across the operating band and a peak gain of about 9 dBi at 11 GHz.