一种新型圆极化UHF通用型RFID读写器天线

面向超高频(UHF)通用型射频识别(RFID)读写器天线的应用需求,设计了一款完全覆盖全球UHF(840-960MHz)频段的RFID圆极化读写器天线。天线采用平面缝隙贴片结构,以共面波导(CPW)馈电方式实现宽频带圆极化特性。测试结果表明,天线的阻抗带宽为735-1014MHz(S11<-10dB),相对带宽31.9%,并且在840-960MHz频段内S11<-20dB,3dB轴比带宽为838-1134MHz,相对带宽30.0%,工作频带内有大于3.5dBi的平坦增益。仿真结果与测试结果基本吻合,天线结构精简,易于加工,满足全球UHF RFID读写器天线的应用需求。     

CPW无空气桥功分器设计及其在阵列天线中的应用

针对传统微带圆极化阵列天线存在带宽较窄、尺寸较大等问题,提出一种新颖的基于共面波导(CPW)槽线转换结构的无空气桥功分器,并基于此功分器设计了一款紧凑型高定向性圆极化阵列天线。设计的共面波导功分器利用共面波导奇模式方法实现了能量分配,不需使用空气桥结构及四分之一波长匹配线,因此尺寸更加紧凑,结构更加简单。利用此功分器设计的圆极化阵列天线剖面厚度仅为1 mm,轴比带宽为4.14%,阻抗带宽为7.03%;在5.8 GHz时,实测增益为8.412 dBi,在保证低剖面、小尺寸的同时,可提供足够的工作带宽以及天线增益。     

倒L形枝节加载宽带圆极化缝隙天线

设计了一种倒L形枝节加载宽带圆极化缝隙天线。天线为单层矩形结构,采用共面波导(CPW)馈电,通过在馈线上端加载倒L形枝节和在环形接地面上加载T 形枝节,实现了天线的宽阻抗带宽和宽轴比带宽特性。实测结果表明,S11 ￡-10 dB 的阻抗带宽达到115%(1.6-5.9 GHz),轴比￡3 dB 的圆极化带宽为48.3% (2.2-3.6 GHz)。该天线结构简单、易于制作,具有较好的应用前景。     

圆极化微带贴片天线辐射和散射特性研究

提出了一种改进的宽带圆极化微带天线。该天线采用单端口、共面波导馈电。通过仿真优化,获得了32.7%的圆极化轴比带宽(AR<3dB),和47.6%的阻抗带宽(VSWR<2.0)。测量天线样机的阻抗带宽为44.4%,较好地吻合了仿真计算结果。最后,以设计天线为例,研究了圆极化微带贴片天线的辐射特性和散射特性,为圆极化天线雷达截面减缩技术打下了良好的理论和实验基础。     

顺序旋转馈电背腔圆极化天线阵列

主要描述了一种基于顺序旋转馈电网络构成的背腔式缝隙圆极化天线阵.天线单元是一种低轮廓的背腔共面缝隙天线,包括运用介质填充的金属背腔和共地共面波导构成的馈电单元.该天线单元带宽为170 MHz,最大增益为5.7 dBi,其厚度小于λ0/50.而天线阵采用2×2天线单元顺序旋转馈电的方法来实现圆极化,其阻抗带宽和3 dB轴...     

面向车载GPS应用的共面波导馈电光透明天线北大核心CSCD

本文以车载GPS应用为基点，以氧化铟锡（ITO）透明导电薄膜为关键材料，设计了一款共面波导馈电的圆极化可见光透明天线。所提出的天线通过将T形贴片从接地板水平延伸向矩形缝隙中心获得圆极化波，在保证80%透明度的前提下实现了575MHz的阻抗带宽和285MHz的轴比带宽，以及3.1dBic的天线增益和47%的辐射效率。天线具有良好的辐射特性，在车载场景等有广泛的应用前景。     

腔体加载式圆极化波导缝隙天线设计

圆极化天线由于其自身具有的众多优点,在现代通信系统中日益受到广泛关注。设计了一种通过在传统波导缝隙天线上加载旋转矩形腔体实现圆极化辐射的天线形式,分析了腔体辐射圆极化波的机理以及腔体对天线阻抗带宽的影响。该天线具有阻抗特性和圆极化特性独立可调的优点。加工实现了一种工作于X频段、具有1×10个单元的天线结构。测试结果表明,在中心频率处右旋圆极化增益约为16.5 d B,主辐射方向上轴比优于1 d B,阻抗带宽(VSWR<2)约为64 MHz。测试结果与仿真数据取得了较好的一致性。     

一种新型UHF RFID阅读器圆极化天线

传统的圆极化阅读器天线采用单馈电微带天线方式设计,频带窄、极化特性较差。在单馈电微带天线的基础上,采用探针馈电曲线贴片的方式,在圆形铁片上开了4个对称的方形缝隙,最终设计出一种新型的UHF RFID圆极化阅读器天线。天线的结构尺寸为167.5 mm×167.5 mm×3 mm,阻抗带宽为870~936 MHz,3 dB轴比带宽为900~918 MHz,最大增益为3.5 dB。与传统的圆极化阅读器天线相比,设计的天线频带宽,且极化特性得到良好改善,能够满足工程上的应用需求。     

小型化窄条形宽带柔性天线

设计了一款小型化窄条形宽带柔性天线,该天线由辐射片和带有短路枝节的共面波导金属地构成,整体尺寸为24.5 mm×5.0 mm×0.1 mm。通过采用带有短路枝节的共面波导金属地、新共面波导结构、两个U型缝隙、馈线倾斜焊接等方法,有效增加了阻抗带宽,且与常规柔性天线相比尺寸减小70%。测试结果表明,天线用于超宽带定位系统中的智能手表时,工作频段覆盖3.27～4.55 GHz,带宽内增益大于2.4 dBi,不圆度小于0.95 dB。     

具有谐波抑制功能的共面波导轻薄整流天线

为解决对无人机、平流层飞艇等空中移动目标无线输能时机载接收端整流天线质量大,占居飞行器有效载荷多的难题,设计了一种具有谐波抑制功能的共面波导轻薄圆极化整流天线。该整流天线采用集中式整流方式,通过将整流电路直接集成在微带天线接地板上,实现了质量轻,尺寸小,剖面低,易共形的圆极化整流天线。该天线工作在5.8 GHz,采用共面波导耦合馈电,并在馈线上直接加载共面波导谐振结构进行谐波抑制,具有较宽的工作带宽。整流电路采用倍压整流形式,利用贴片电容作为直通滤波器进行直流滤波,电路结构简单。该整流天线结构紧凑,质量仅6.28 g,剖面厚度0.5 mm,最佳整流效率63.84%,测试结果与仿真结果吻合良好,验证了该设计的可行性。     

Broadband CPW-fed folded-slot monopole antenna for 5.8 GHz RFID application

A folded slot is introduced to expand the impedance bandwidth and miniaturise the size of a coplanar waveguide (CPW)-fed patch monopole antenna for radio frequency identification (RFID) applications. The designed antenna, which, including ground plane, is only 13 mm in height and 11 mm in width, can operate at the 5.8 GHz band with measured impedance bandwidth and average antenna gain of 30% and /spl ges/5 dBi, respectively, and also conical radiation patterns. These properties make the antenna suitable for RFID tags.     

An RFID Tag Using a Planar Inverted‐F Antenna Capable of Being Stuck to Metallic Objects

This letter presents the design for a low‐profile planar inverted‐F antenna (PIFA) that can be stuck to metallic objects to create a passive radio frequency identification (RFID) tag in the UHF band. The designed PIFA, which uses a dielectric substrate for the antenna, consists of a U‐slot patch for size reduction, several shorting pins, and a coplanar waveguide feeding structure to easily integrate with an RFID chip. The impedance bandwidth and maximum gain of the tag antenna are about 0.3% at 914 MHz for a voltage standing wave ratio (VSWR) of less than 2 and 3.6 dBi, respectively. The maximum read range is about 4.5 m as long as the tag antenna is on a metallic object.     

Triple-band CPW-fed compact monopole antennas for GSM/PCS/DCS/WCDMA applications

A triple-band coplanar waveguide (CPW)-fed LI-shaped monopole antenna is proposed. The antenna is composed of an I-shaped monopole and a meandered L-shaped one. The dimensions of the design are 29 times 28 mm which are 0.077 lambda times 0.075 lambda in terms of the lowest operating frequency of 800 MHz. The antenna operation presents attractive characteristics, each monopole is independently optimised to the resonant frequency and the impedance bandwidth without affecting those of other bands. The antenna shows improved radiation efficiency of individual monopoles for a global system for mobile communication, personal communication systems, digital communication systems, and wireless code division multiple access applications.     

CPW-fed folded-slot antenna for 5.8 GHz RFID tags

A coplanar waveguide (CPW)-fed capacitive folded-slot antenna is proposed for the radio frequency identification (RFID) application at 5.8 GHz. The antenna is fabricated on a 30/spl times/30 mm substrate. The measured bandwidth and antenna gain are 7.5% and 4.2 dBi, respectively. Radiation patterns are almost omnidirectional in the H-plane. These properties and the compact and uniplanar structure make the antennas suitable for use as RFID tags.     

Near-Field Loop Antenna for the UHF RFID Reader

A loop antenna for near field readers is proposed.Through periodic interdigital capacitors,the phase of the current on the loop is compensated and kept in phase.Hence,a loop with a perimeter of one wavelength at 900 MHz achieves a uniform near magnetic field distribution inside the loop.A novel method is proposed to evaluate the performance of the coplanar waveguide (CPW) to coplanar stripline (CPS) transition,which is used as a balun for the feeding network in this paper.This loop antenna has a 70 MHz operating bandwidth and 12 cm maximum reading range when the output power is 24 dBm,which is suitable for most near field radio frequency identification (RFID) applications.     

Compact CPW-fed monopole antenna for 5 GHz wireless application

A compact and simple coplanar waveguide (CPW)-fed monopole antenna for 5 GHz wireless communication is proposed. By properly adjusting the lengths of both the monopole strip and the inverted L-shaped ground, the designed antenna, with, including ground plane, only 9/spl times/9.5 mm/sup 2/, can operate at the desired 5.2 or 5.8 GHz band. The electromagnetic coupling effect between the radiating strip and the ground on excitation of the resonant mode has been studied. Prototypes of the proposed antenna have been constructed and experimentally studied. Measured results show a -10 dB impedance bandwidth and an average antenna gain of 400 MHz and >6 dBi, respectively.     

小型化超宽带印刷单极子天线

该文提出一种小型化超宽带印刷单极子天线,阻抗带宽为3．17～50GHz。该天线采用圆彤单板子为辐射结构,利用共而波导馈电方式．天线的尺寸为30×32×1．6mm,通过适当地调整板尺寸和阋形辐射单元的半径,可以使天线得到很好的阻抗匹配。与以往的天线相比,带宽更宽,尺寸更小,天线具有良好的辐射性能,达到了小型化的婪求．可为将来的超宽带通信应用提供良好的选择。     

一种应用于三频GPS的宽频带单馈电天线设计

为了实现全球定位系统（global positioning system,GPS）天线小型化并提高其性能,提出了一种新型的三频段GPS宽频带单馈电背腔天线,可在1176.45 MHz（L5）、1227.60 MHz（L2）和1575.42 MHz（L1）三个GPS频段下工作。通过在一端馈送交叉型行波天线并在另一端添加负载,来实现提出天线的右旋圆极化（right-hand circular polarization,RHCP）,且配有弯折线散热器。天线尺寸仅为120×120×29 mm3。仿真和实际测量结果显示,提出的单馈电天线无需使用复杂的馈电网络或双馈结构便可提供宽阻抗带宽（VSWR<2）、低轴比（AR）（<2 dB）和高RHCP增益（>4 dBic）。     

一种UHF频段RFID阅读器天线的小型化设计

采用1／4波长微带贴片以缩小天线面积,利用商业软件Ansoft HFSS10．0进行设计仿真和优化,成功研制了一款可用于UHF频段（915MHz）RFID读写器的小型化微带天线。经过实际测试,天线在工作频段内性能优良,驻波比FSWR〈2时阻抗带宽达到30MHz。贴片天线的尺寸与性能完全满足手持RFID阅读器的需求。