无源超高频抗金属标签天线设计方法综述

射频识别( RFID)技术的不断发展,对标签天线提出了更高的要求。普通标签天线直接应用于金属表面时,由于受到金属边界的影响,其性能会出现一定程度的下降。详细介绍了4种无源超高频抗金属标签天线的设计方法,包括调整天线与金属面的间距、采用吸波材料、引入高阻抗表面基板、采用平面倒F天线( PIFA)或微带天线结构,并分析了每种方法的优缺点及其对标签天线的阻抗匹配、带宽、尺寸、识别距离以及成本等方面的影响。微带贴片天线不仅具有低剖面、高方向性等优点,而且含有金属接地板,常用作抗金属标签天线的设计原型。在抗金属标签天线的设计与实际应用中,研究者可针对具体要求灵活运用这些设计方法。     

双圆环电视接收天线

双圆环电视接收天线(以下简称双环天线)由两副圆环天线并接构成。其中,每一副圆环天线的周长约等于1个波长。为了改善天线的性能,这种天线在实际应用时都带有金属反射网(或金属反射板),如图1所示。这种天线与单圆环天线相比,其特点是增益高,定向性好,抗后向干扰能力强。因此,获得了越来越广泛的应用。双环天线之所以具有上述特点,是与配置金属反射网(板)有密切关系。下面就金属反射网的作用与安装、天线的馈接方法及天线的应用作一介绍。     

用于手术刀的抗金属无源RFID 标签天线设计

为了加强对医疗器械的跟踪管理,尤其是对手术前后手术刀数量的有效监测,设计了一款可应用于手术刀的小型化超高频(UHF)抗金属射频识别(RFID)标签天线。该天线采用短路短截线结构,可嵌入金属或贴敷于金属表面。标签天线由辐射面、短路短截线、金属地面以及标签芯片构成,通过采用高介电常数介质基板达到天线小型化的目的,通过对天线辐射面、短路短截线及开口尺寸的调整,可实现对天线谐振频率以及天线特性阻抗的调节。天线总体尺寸为66mm×5mm×0.8mm。标签天线嵌入手术刀柄中最大读写距离为1m。根据仿真优化结果加工制作天线实物,该标签天线的测试数据与仿真结果比较吻合,测试结果表明该天线可应用于手术刀。     

基于PDMS的柔性可拉伸天线的仿真与测试

本文设计了两款柔性单极子天线，并且它们具有重量轻、体积小、易拉伸等特点。采用ANSYS HFSS对天线的射频性能进行仿真，并使用ANSYS Workbench对天线进行位移形变拉伸，天线最大形变为拉伸方向天线长度的30%。天线用柔性材料聚二甲基硅氧烷(PDMS)为质基底，天线由液态金属(镓铟合金8：2，EGaIn)为导电材料并涂附在PDMS上，最后由PDMS将液态金属导电材料进行封装避免泄露，天线采用共面波导(CPW)的馈电方式。对制作后的天线进行拉伸测试，测试结果表明，在10%-30%的拉伸条件下，该天线都能保持原来稳定的工作特性。     

基于PDMS嵌入式超宽带天线设计

设计了一种以柔性材料聚二甲基硅氧烷(PDMS)为介质基片的超宽带(UWB)天线,其辐射单元由矩形和半圆环金属贴片组成,两部分结构由带状贴片连接,采用共面波导方式馈电。上述金属贴片嵌入在PDMS基片中间,用于人体通信的可穿戴系统。利用嵌入式结构,有效提高了天线的柔韧性和耐用性。为了更好地模拟天线在人体表面的工作环境,构建了包括皮肤、脂肪和肌肉的三层人体组织模型,满足人体安全的国际标准的最大天线比吸收率值为16.4 mW。最后对天线样品进行测试,结果表明天线总体性能稳定,阻抗带宽为5.39-10.33 GHz,实现了在医学机构使用的频段(5.725-5.875 GHz)要求。     

基于液态金属的频率可重构天线新设计

提出一种新型的液态金属频率可重构天线设计方法。以对称振子天线为原型,采用镓铟液态合金(EGaIn)为辐射元,将其包裹在微流体通道内。在天线适当位置开口添加绝缘片,呈断路状态;撤掉绝缘片,利用液态金属自我修复性能,加热挤压切口使其愈合,呈通路状态;通过调节绝缘片的位置实现1.6~3.0 GHz频率范围内的重构,并通过曲线拟合提出了适合该天线的工作频率估算公式。仿真结果表明天线具有良好的带宽、阻抗特性,并保持较高增益,辐射性能良好。     

基于液态金属的频率可重构天线新设计

提出一种新型的液态金属频率可重构天线设计方法。以对称振子天线为原型,采用镓铟液态合金(EGaIn)为辐射元,将其包裹在微流体通道内。在天线适当位置开口添加绝缘片,呈断路状态;撤掉绝缘片,利用液态金属自我修复性能,加热挤压切口使其愈合,呈通路状态;通过调节绝缘片的位置实现1.6~3.0 GHz频率范围内的重构,并通过曲线拟合提出了适合该天线的工作频率估算公式。仿真结果表明天线具有良好的带宽、阻抗特性,并保持较高增益,辐射性能良好。     

一种新型宽带金属腔体天线

介绍了一种新型宽带金属腔体天线。天线采用纯金属设计,天线包括扁盒状空心的金属腔体与一层金属盖板,金属盖板上开工字形缝隙与‘［］’形缝隙,分别谐振于不同频率。腔体有效展宽了天线的阻抗带宽,使天线实现良好的宽频带特性,43%工作带宽内驻波比小于2,天线剖面约为低频波长的1/6,具有低剖面的优点。对X波段8×12单元实验阵的测试结果表明,该天线在43％的频段内具有良好的阻抗匹配性能及较高的工作效率。天线具有结构简单、材料单一、易加工、强度高、散热性好、环境适用性强的特点。     

应用于带有闭合金属边框手机的缝隙天线

提出了无断开(闭合)金属边框情况下平面手机天线的模型,解决了在闭合金属情况下导致的传统平面天线带宽变窄的问题.通过天线折叠技术,将其面积缩小至手机应用的尺寸内.然后,进一步的阻抗匹配使在smith圆图上将天线的阻抗带宽调到了最大,使天线能够覆盖GSM850、GSM900、DCS、PCS、UMTS 5个频段.采用开槽天线将金属边框作为天线的一部分能解决金属框对天线的影响.实测结果表明,低频部分带宽为142 MHz,高频部分带宽有480 MHz,满足了常用频段的需要.同时,为了避免发生手握的影响,金属框和地的接地点置于电路基板顶段,从而降低了手握的影响.     

低RCS宽带磁电偶极子贴片天线设计

该文设计了一种低雷达散射截面(RCS)的宽带磁电偶极子贴片天线,其中印刷在介质板上的金属贴片为电偶极子,3个金属过孔连接辐射贴片与金属地板构成磁偶极子。整个天线采用T型渐变馈电结构同时激励电偶极子与磁偶极子,天线的频带范围为7.81~13.65 GHz,覆盖了整个X波段。实测和仿真结果表明,通过在磁电偶极子贴片天线底面采用开槽技术并优化开槽的形状、大小、位置等变量,在天线工作频带范围内实现了RCS的减缩,最大缩减量达到了17.9 dB,同时天线保持了增益稳定不变,E面、H面方向图一致的特性。     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks     

Call for Papers—Feature Topic,Vol.12,No.7,2015

正Information Centric Networking Information-Centric Networking(ICN) is an emerging direction in Future Internet architecture research,gaining significant tractions among academia and industry.Aiming to replace the conventional host-to-host communication model by a data-centric model,ICN treats data content as the first     

JOURNAL OF ELECTRONICS(CHINA)

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NEXT GENERATION WIRELESS NETWORKS–ESPECIALLY THE USE OF MILLI-MICROWAVE BANDS

The global bandwidth shortage of wireless communications has motivated the exploration of the naillimeter wave （ram-wave） frequency spectrum for the next generation wireless communications. Recent advances in RF CMOS technology and high speed baseband signal processing technologies have enabled tile extensive research and development of turn-wave wireless communications. The multi gigabit per second data rate of ram-wave system will lead to applications in many important scenarios, such as WPAN, WLAN,back-haul for cellular system. And the frequency bands include 28 GHz, 38 GHz, 45GHz, 60GHz, E-BAND and even beyond 100 GHz. The propagation and the imitation of the RF circuits design in these frequency bands make the directional antennas be inevitable for mm-wave communications.