新型WLAN平面倒F双频天线的设计

提出了一种新型的应用于2.4/5GHz蓝牙和无线局域网的双频内置平面倒F天线。该天线结构紧凑,可以方便地植入无线通信设备中,有较强的实用性。通过加载F形槽和阶梯形槽使天线能够满足无线局域网中小型化双频天线的技术要求。天线在蓝牙频段阻抗带宽达到300MHz(2.21~2.51GHz),在无线局域网频段阻抗带宽达到1070MHz(4.95~6.02GHz),辐射方向图表明该天线全向性能较好,增益在3.1~6.7dBi范围内。     

一种用于笔记本电脑的双频段八天线系统

提出了一种应用于笔记本电脑的双频段八天线系统.该八天线系统由一个四天线系统、两个双天线系统和两个T形谐振带构成.在分析了四天线系统和两个双天线系统的耦合机理后,提出了减小耦合的方法.实测结果表明:天线样品在2.4-GHz无线局域网(Wireless Local Area Network,WLAN)频段的-10 dB公共阻抗带宽为90 MHz(2.4～2.49 GHz),在5.2/5.8-GHz WLAN频段的-10 dB公共带宽为0.9 GHz(5.15～6.05 GHz),其中在5.15～5.19 GHz频段内的反射系数为-9.5～-10dB;八个天线单元在2.4/5.2/5.8-GHz WLAN频段内的互耦均低于-15 dB;在2.4-GHz和5.2/5.8-GHz WLAN频段内的增益分别高于2.7 dBi和3.3 dBi、效率分别高于53％和65％.根据实测三维辐射方向图计算了八天线系统的包络相关系数.     

宽带平板天线的设计与仿真

基于CST软件设计了一种宽带平板天线,在由4个偶极子组成的阵列下方放置一块金属反射板形成定向天线,通过在平板上采用周期结构反射器来扩大天线的带宽,并结合这种方法,设计了工作在760 MHz～1220 MHz的大线,在此频段内VSWR ＜2,增益高达10.5 dBi.该天线的带宽很宽,且定向性很好,具有广阔的应用前景.     

一种频带展宽的小型化左手偶极子天线的设计

左手传输线加载偶极子(简称左手偶极子)可以有效实现天线的小型化,但是这种天线通常带宽窄、效率低。通过采用一种渐变的梯形网络结构代替传统的非渐变的结构形式来改善天线的阻抗特性,设计了四单元的左手偶极子天线,进而拓展了天线的带宽,天线总长度为0.2。仿真和实物测试结果显示:天线同时工作在–1阶和–3阶谐振模式,|S11|≤–10 dB的阻抗带宽达到6.5%,在工作频段内(571~610 MHz),天线的增益不小于–4.25 dBi,效率大于25%。     

采用螺旋线实现高隔离度的车载多频宽带MIMO天线

为解决车载天线工作带宽窄和MIMO天线低频段隔离度低等问题,提出一种应用于车载通信系统的多频宽带高隔离度的MIMO天线,其工作频段为824～960 MHz和1 710～6 000 MHz,可覆盖民用移动通信的2G/3G/4G/5G和无线局域网/车联网等频段。单极子天线单元采用弯曲、开槽等诸多技术实现多频宽带,还通过添加接地枝节来降低天线高度和提高物理稳定性;在MIMO天线设计上采用螺旋线来提高天线单元之间的隔离度。实测结果表明,天线在工作频段内的反射系数小于-10 dB,隔离度小于-20 dB,低频段增益和辐射效率略低,中高频段的增益均大于4 dBi,最高达到7 dBi,效率均高于70%,最高可以达到96%。实测数据与仿真数据具有良好的一致性,所研制的天线可满足车载天线对多频段通信和高隔离度MIMO天线的技术要求,其结构和尺寸专为安装于汽车内部中控台背面而设计。     

基于磁电偶极子的宽带高增益天线设计

基站天线的设计趋于覆盖多模态频段的宽带模式发展。传统的宽带天线在实现覆盖大带宽的基础上,其增益却在工作带宽内平坦度变化较大。磁电偶极子天线在覆盖大带宽的同时可保证实现稳定的增益。本文设计了一款应用于3G/4G/5G的多模态宽带的双极化磁电偶极子天线,带宽为1.8-5GHz,其相对带宽大于94.1%。天线增益在工作带宽内均值大于9dBi,峰值增益为10.5dBi,增益平坦度变化较为平缓,且天线结构简单。     

一种紧凑的双频混合圆柱形介质谐振器天线研究

为实现天线的小型化和多频段频率特性,提出了一种双频混合圆柱形介质谐振器天线。该天线通过将圆形铜带加载到介质谐振器天线的顶部,可以在4.4和6.1 GHz处谐振,并且-10 dB带宽分别为600 MHz和500 MHz。使用矩形槽激励圆柱介质谐振器的HEMY11和HEMX11模。此外,可以通过调整寄生条带宽度和间隙来独立地控制较高频段。实验结果表明,该天线具有良好的增益(4.4 GHz时为4.9 dBi,6.1 GHz时为5.6 dBi)、效率高(所有工作频段均大于88%)和良好的天线前后比(两个主平面上均大于10.08 dB),可有效适用于5G和WiFi融合组网。     

一种新型的高增益低剖面天线

为了解决传统天线低增益、窄频带和大尺寸的问题,提出了一种新型的高增益低剖面天线。该天线采用人工磁导体(AMC)作为反射面,具体结构是将双面印刷蝶形天线作为辐射天线悬置在5×7梅花单元反射面上。经优化,该天线的中心频率为2.58 GHz,相对带宽为11.63%,覆盖了LTE(长期演进)中的2 500～2 690 MHz频段,且天线的总体高度仅为9.5 mm,相当于自由空间波长的1/12。此外,该天线的峰值增益达到9.7 dBi,证实了新型天线的可行性。     

双频一体化超宽带探地雷达天线设计

针对目前探地雷达(Ground Penetrating Radar, GPR)产品单一频段工作所导致的耗时费力、效率低等缺点,文中设计实现了一种中心频率分别为400 MHz、1 000 MHz且带宽为200～1 500 MHz的双频一体化复合阵列天线,并将其应用于超宽带(Ultra-Wide Band, UWB)探地雷达系统中。阵列天线包含3个中心频率为400 MHz和6个中心频率为1 000 MHz的蝶形天线,具备双频段同时探测能力,可实现一条测线含两种不同频段的探测结果,克服了传统探地雷达不同频率的重复探测问题,增强了探地雷达系统的实用性。所提出的双频一体化探地雷达天线具有超宽带、高增益、波束窄等特点,其相对带宽为153%,整个带宽内最高实现17.6 dBi峰值增益,半功率波束宽度最窄为7.6°,为高分辨率、高效率探地雷达应用提供了一种新的天线方案。     

一种新型VHF双频宽带高增益全向天线

提出了一种工作在VHF频段的双频宽带中馈垂直极化高增益全向天线.天线采用中馈套筒天线结构形式,在天线上、下辐射体中部分别串接一个高频倒相线圈,天线底部加同轴扼流圈的设计方案.该天线在30 MHz～110 MHz和176 MHz～300MHz频带内具有良好的辐射特性,水平面增益为2～6dBi.     

Beam steerable square loop antenna over hybrid high impedance surface

A novel hybrid high impedance surface is presented and a beam steerable four feed square loop antenna is built on this structure. At a test frequency of 4.7 GHz, the proposed hybrid high impedance surface based square loop antenna is 4.69 mm high and has an impedance bandwidth of 650 MHz and directivity of 8.7 dBi. Compared with the earlier reported steerable square loop antenna the new antenna s performance equates to a thickness reduction of 61, bandwidth enhancement of 150 , a directivity improvement of 2 dBi, a co-polar sidelobe reduction of 11 dB, and a cross-polarisation sidelobe reduction of 5 dB.     

230MHz无线专网小型化平板天线设计

提出了一种用于电力230 MHz无线专网的平板天线,天线工作频率228～237 MHz,相对带宽3.9％.该天线由单层1 mm厚度FR4印制板的倒F结构辐射体组成,天线整体尺寸300 mm×260 mm×1 mm.天线通过匹配传输结构将馈电点放置于辐射体背部,便于安装.经过仿真天线增益性能良好,水平全向增益1.5 dB...     

一种超高频射频识别读写器天线

本文提出了一种适用于我国UHF RFID读写器的宽带圆极化叠层微带天线,通过选用廉价FR4板、空气层介质和对角线切角的正方形贴片组成叠层结构,采用S型水平蜿蜒带条激励主辐射贴片的馈电方式,展宽了天线的阻抗带宽和轴比带宽.所提出的S型水平蜿蜒带条馈电技术,实现了对称的辐射方向性图.给出了天线设计思路,并利用电磁仿真软件分...     

Shorting strap tunable single feed dual-band PIFA

RF switches are integrated to the shorting straps of a single feed dual-band planar inverted-F antenna (PIFA) to make a tunable PIFA. The L-band switch yields 0.45-dB insertion loss (IL) and 10-dB isolation bandwidth (BW) of 40% at 1.5 GHz. The tunable PIFA yields 39% impedance BW at 900-MHz band and 7.8% BW at 2000-MHz band. The measured radiation patterns are nearly omni-directional and yield a gain of -7.8 dBi at 652 MHz and 4.3 dBi at 2104 MHz.     

Dual Band Planar Spiral Feed Backed by a Stepped Ground Plane Cavity for Satellite Boresight Reference Antenna Applications

This paper presents development of a new planar spiral feed for a satellite boresight reference antenna, operating at two widely separated frequency bands (2200–2300 MHz and 8000–8400 MHz). A stepped ground plane cavity with different quarter wavelength distances is proposed to provide unidirectional patterns at these frequency bands. A back lobe suppression of around 12 dB in 2 GHz band and better than 15 dB in 8 GHz band with a measured on-axis axial ratio of less than 3 dB is achieved for the dual band planar spiral feed with stepped ground plane cavity configuration. A boresight reflector antenna employing this feed has measured beamwidths of 7 degrees and 1.8 degrees respectively and gain of 26 dBi and 36 dBi at 2250 MHz and 8200 MHz.      

Accordion shape monofilar axial mode helix for RFID reader

An accordion shape monofilar axial mode helical antenna designed by curving the helix along the axis is proposed. This antenna achieves a low-profile characteristic as the 10-turn helix's axial length is 0.354/spl lambda/. The impedance bandwidth (SWR<1.5) is 9% from the frequency of 880 to 963 MHz and the axial ratio bandwidth (AR<3 dB) is 6.5%. The measured gain is 10.2 dBi. This antenna operated at the centre frequency of 915 MHz and has a tilted radiation of 17/spl deg/ to the curving side.     

Broadband Stacked Patch Antenna with Low VSWR and Low Cross‐Polarization

A low cross‐polarization broadband stacked patch antenna is proposed. By means of the stacked patch configuration and probe‐fed strip feed technique, the VSWR 1.2:1 bandwidth of the patch antenna is enhanced to 22% from 804 MHz to 1,002 MHz, which outperforms the other available patch antennas (<10%). Furthermore, the antenna has a cross‐polarization level of less than ?20 dB and a gain level of about 9 dBi across the operating bandwidth. Simulation results are compared with the measurements, and a good agreement is observed.     

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。     

Design and optimization of a non-cross feed printed log periodic dipole array antenna using particle swarm optimization

This paper presents an optimized design of non-cross feed Printed Log Periodic Dipole Array (PLPDA) antenna using Particle Swarm Optimization (PSO) technique. An improved feed structure of non-cross fed dipoles is chosen as reference antenna, which avoids the complexity of conventional feeding with long coaxial line and CPW feed. A simple fitness function based on S₁₁ parameter is used in PSO to achieve the goal of size reduction and bandwidth enhancement. Simulation results on CST software are verified by a manufactured prototype of proposed PSO optimized non-cross feed PLPDA antenna using FR 4 substrate with a thickness of 1.6 mm. The measured bandwidth of proposed antenna is 4.2–11.6 GHz with a fractional bandwidth of 93.6%, whereas the reference antenna covers the frequency range from 4.2 to 9.2 GHz with a fractional bandwidth of 74.6%. The effective area of the proposed design is 30% lesser than reference antenna. Proposed antenna is offering peak gain of 7.6 dBi with an average gain of 5.5 dBi in desired band. The electrical size of optimized structure is 0.53λ at center frequency. Thus, proposed antenna is offering higher bandwidth and significantly smaller size with less complexity and lower cost, while maintaining the log periodic nature and gain.     

手持终端波束成形天线阵列的优化设计

设计了一款适用于移动手持终端的低剖面波束成形天线阵列。该天线阵列由八个结构相同的倒F天线组成,可以工作在GSM1900(1880~1920 MHz)、LTE2300(2300~2400 MHz)和LTE2500(2540~2620 MHz)三个频段。通过功率传输效率最大化理论,可以优化出该阵列在所需方向上的最佳激励。通过馈电电路板给8个天线单元提供优化的激励,可以将天线波束偏转到所需方向,并且保证天线在该方向上获得最大可能增益。天线阵列工作在2.45 GHz时,在x、y、z方向上的增益分别为7.80、6.03和7.20 dBi;相应地,在1.9 GHz时分别为6.67、5.27和6.05 dBi。