Multiband printed monopole and dipole antenna with square-nested fractal

A kind of novel multiband antenna with square-nested fractal is proposed and designed, including printed monopole antenna and dipole antenna, which are nested with a series of similar square elements. The antennas can synchronously operate in multiple frequencies, covering the four required frequencies, 24GHz/35GHz/52GHz/58GHz, for WLAN/WiMAX application. The antenna surface currents are simulated by CST MWS, a three-dimension full-wave electromagnetic simulator, and the multiband operating mechanism has been explained from analysis of the simulation results. Then the models of the two proposed antennas fed by coplanar waveguide (monopole antenna) and balanced microstripline (dipole antenna), respectively, have been obtained. Finally, prototypes of the two antennas have been manufactured and measured in anechoic chamber. The results well match the simulation results, which verifies the feasibility of design idea. Moreover, these antennas are miniature and the design idea can be easily applied into other types of nested structure, the features of which make the proposed antennas have promising application in multiband fields.

Double U-Shaped Slots Loaded Stacked Patch Antenna for Multiband Operation

The design of a seven-band stacked patch antenna for the C, X and Ku band is presented. The antenna consists of an H-slot loaded fed patch, stacked with dual U-slot loaded rectangular patch to generate the seven frequency bands. The total size of the antenna is 39.25 × 29.25 mm2. The multiband stacked patch antenna is studied and designed using IE3D simulator. For verification of simulation results, the antenna is analyzed by circuit theory concept. The simulated return loss, radiation pattern and gain are presented. Simulated results show that the antenna can be designed to cover the frequency bands from (4.24 GHz to 4.50 GHz, 5.02 GHz to 5.25 GHz) in C-band application, (7.84 GHz to 8.23 GHz) in X-band and (12.16 GHz to 12.35 GHz, 14.25 GHz to 14.76 GHz, 15.25 GHz to 15.51 GHz, 17.52 GHz to 17.86 GHz) in Ku band applications. The bandwidths of each band of the proposed antenna are 5.9%, 4.5%, 4.83%, 2.36%, 3.53%, 1.68% and 1.91%. Similarly the gains of the proposed band are 2.80 dBi, 4.39 dBi, 4.54 dBi, 10.26 dBi, 8.36 dBi and 9.91 dBi, respectively.

Design of a Multiband Patch Antenna for 5G Communication Systems

Currently, communication system requires multiband small antennas for 5G mobile applications. Driven this motivation, this paper proposes a multiband patch antenna for Wi-Fi, WiMAX and 5G applications. The proposed antenna can effectively operate at 2.4 GHz as Wi-Fi, 7.8 GHz as WiMAX and 33.5 GHz as 5G communication purposes. The proposed antenna arrays have given directional radiation patterns, very small voltage standing wave ratio, high gain (VSWR) and directivity for each aforementioned systems operating frequency. This antenna is made for multiband purpose which can be effective for not only Wi-Fi and WiMAX but also 5G applications.

A Compact Tri-Band Antenna Based on Inverted-L Stubs for Smart Devices

We designed and constructed a novel,compact tri-band monopole antenna for intelligent devices.Multiband behavior was achieved by placing inverted-L shaped stubs of various lengths in a triangular monopole antenna fed by a coplanar waveguide.The resonance frequency of each band can be controlled by varying the length of the corresponding stub.Three bands,at 2.4(2.37-2.51),3.5(3.34-3.71),and 5.5(4.6-6.4)GHz,were easily obtained using three stubs of different lengths.For miniaturization,a portion of the longest stub(at 2.4 GHz)was printed on the opposite side of the substrate,and connected to the main stub via a shorting pin.To validate the concept,the antenna was fabricated on a low-cost 1.6-mm-thick FR-4 substrate with dimensions of 20×15×1.6 mm^(3).The antenna exhibited a moderate average gain of 2.9 dBi with an omnidirectional radiations over the bandwidths required for RFID,Bluetooth,ISM,WiMAX,andWLAN-band applications.These features make the antenna suitable for compact smart devices.

Dielectric Loading on Multi-Band Behaviors of Pentagonal Fractal Patch Antennas

This paper describes the multiband behaviour as well as the response for dielectric loading of a pentagonal fractal patch antenna designed at frequency f = 2.45 GHz. The proposed antenna shape has been obtained by introducing slots in a pentagonal patch antenna up to second iteration. Detailed design steps and results of the designs are studied and investigated in this paper. Simulated and measured results reveal that the antenna will be operated at three different frequency bands—2.17 GHz, 3.56 GHz, and 7.93 GHz with acceptable performances (i.e. VSWR < 2). The measured results for the antennas are in good agreement with simulated results. The proposed antenna maintains good radiation pattern with gain. However dielectric loading increases its radiation efficiency at the cost of significant decrease in gain and directivity.

On the Design of Plus Slotted Fractal Antenna Array

A new technique which is a combination of fractal antenna and array antenna is presented to design Plus Slotted Fractal Antenna Array (PSFAA) in this paper. PSFAA with corporate feed operates at 2.5 GHz frequency. PSFAA is designed on FR4 substrate material with permittivity 4.4 and height 1.6 mm. PSFAA is designed up to 2nd iteration. High Frequency Structure Simulator (HFSS) software is used for simulation of PSFAA. The proposed antenna array operates at three bands with five frequencies 2.5 GHz, 4.1 GHz, 6.9 GHz, 7.4 GHz and 8.2 GHz. Simulated Return losses results of proposed PSFAA are -22.15 dB, -19.44 dB, -25.21 dB, -10 dB, -12.45 dB at above frequencies respectively. It has a gain of 9.22 dB at resonant frequency 2.5 GHz whereas conventional antenna array has a gain of 5.15 dB at resonant frequency 2.5 GHz. Return losses and gain of PSFAA also improved from conventional antenna array at various resonant frequencies.

Reconfigurable Microstrip Double-Dipole Antennas for Personal Wireless Communications

In this paper, a number of reconfigurable antennas are designed to support multiband and wideband wireless applications in different frequency bands in the range between 1 GHz and 6 GHz. The proposed designs consist of microstrip-fed two dipoles through simplified balun. By controlling the lengths of the dipoles by connecting or disconnecting slots, we are able to change the antenna operating frequency as well as the operation mode. Two modes are supported by all of the proposed antennas: Multiband and Broadband modes.

2.4/4.8/7.2 GHz三频段谐波雷达天线的研究与设计

研究设计了一种应用于手持式谐波雷达的三频段单极子天线。天线采用共面波导馈电,通过在单极子天线主辐射体加载L型辐射枝节、在接近主辐射体的接地平面开三角形切口的方法,使其谐振于2.4 GHz,4.8 GHz和7.2 GHz三个频段。同时,在距离天线10 mm处加载金属挡板,使天线辐射方向性增强,并能接收多个方向反射的电磁波。所实现的天线尺寸为54 mm×53 mm×1.6 mm,在三个工作频段上的带宽分别为0.51 GHz(2.35~2.86),1.39 GHz(4.17~5.56),1.46 GHz(6.17~7.63),能够有效覆盖谐波雷达全部的工作频段;由天线的峰值增益和辐射方向图可知,天线在工作频段内增益性能和整体辐射性能良好。

开槽式六边形多频带高增益微带天线仿真

随着无线通信技术的发展,小型化、多频带微带贴片天线在无线通信中得到了广泛应用。文章设计了一种六边形多频带微带天线,采用同轴线馈电,在六边形贴片的每个顶点内侧进行120°的开槽。通过调整贴片开槽的几何形状和尺寸,能够有效地获得三种不同的谐振模式,可应用于L波段和C波段。用仿真软件CST对该种天线进行仿真及分析,其结果表明,在工作频段均满足增益G≥6 dbi,回波损耗S_(11)<-10 dB。该天线具有结构简单、体积小、增益良好的特点,适用于通信中WiFi频段。

一种小型化五陷波UWB天线设计

为了滤除窄带信号对超宽带(Ultra-Wide Band,UWB)通信系统的干扰以及解决天线尺寸偏大的问题,设计出一种小型化五陷波UWB天线。该天线通过添加L型枝节、C型槽、倒U型槽以及EBG结构,产生五个陷波带。对天线进行回波损耗(S11)、驻波比(VSWR)以及增益(Gain)等仿真测试,通过天线表面的电流分布情况分析了天线的陷波原理,研究上述结构对天线陷波特性的影响。该天线将UWB通信应用与陷波天线技术相结合,最终尺寸为21 mm×16 mm,实现了体积小、频带宽、多频段陷波特性的性能要求,天线频带覆盖了S、C和X三个波段,具有屏蔽窄带信号干扰的作用,可应用于UWB通信系统。测试结果表明,天线的阻抗带宽为2~12 GHz,在工作频段内具有全向性,并且整个UWB频段内天线的增益变化在4 dB以内,最大增益为4.67 dB,在通带频段内,天线五个陷波特性的结果与仿真结果均吻合良好。

一种应用于车载通信的多频段全向天线

文中设计了一种应用于车载通信的多频段全向天线。该天线由印制于FR4介质基板正反两面的金属贴片组成,通过在主辐射贴片上端加载弯折枝节、在侧边加载边缘谐振单元、在背面加载电耦合电感电容(ELC)谐振单元实现了其多频段特性;在主辐射贴片上蚀刻C形槽拓宽了天线的中频带宽;天线的尺寸为58 mm×42 mm×1.6 mm。测试结果表明:S_(11)≤-10 dB的阻抗带宽为0.82~0.96 GHz、1.7~2.69 GHz、3.34~3.66 GHz、4.81~4.97 GHz,覆盖了2G、3G、4G、5G等频段。该天线具有小尺寸、宽频带以及全向性好等优点,可以应用于车载通信或其它移动通信场景。

基于单馈点的多频段及宽带圆极化微带天线研究综述

随着现代无线通信技术的快速发展,圆极化天线因其在减少多径干扰方面的优势而受到越来越多的关注,并已广泛应用于无线通信、雷达、卫星通信等系统中。由于需要传输的信号频率范围较广,因此要求使用多频段或宽频带圆极化天线来实现信号的传输和接收。微带天线具有结构简单、成本低廉、加工方便、剖面低、设计灵活、易于实现多频段及宽带圆极化工作模式等优点,因而得到了广泛的应用和深入的研究。本文首先介绍了研究背景和圆极化天线的基本参数,然后论述了微带天线实现圆极化的基本技术,最后重点阐述了微带天线实现多频和宽带圆极化的几种改进技术。

分形天线的研究进展

论述了分形天线的发展状况 ,介绍了分形天线的分析方法和最新的研究成果。天线的分形设计是电磁理论与几何学的融合。分形天线可以实现多频工作和尺寸减缩 。

八频段手机天线设计

提出了一种新颖的适应于手机终端上的八频段手机内置天线。利用(Planar Inverted-F Antenna,PIFA)天线原理、多带线设计方案,便于实现小型化及多频段的要求,分析了一些重要结构参量对天线性能的影响。仿真结果表明:该天线能够工作在八个常用的无线通讯服务频段,同时具有全向性方向图、增益和辐射效率高的特点,且每个工作频点及带宽可通过调节天线中带线的长度来获得。实际加工做了天线并测试,天线的测试结果与仿真结果具有较好的一致性。所设计的天线体积小、调整方便,可应用于无线通讯中的手机终端。

应用于WLAN/WiMAX的小型化全向三频天线

针对现有小型化多频天线结构比较复杂、天线的全向特性不理想的问题，文中提出了一种可同时工作在WLAN（2．45GHz，5．15～5．85GHz）和WiMAX（3．50GHz）三个频段的天线．该天线采用了变形的顶加载单极天线结构，通过在非主极化方向上引入多频谐振支节，实现了在三个工作频率上的垂直极化全向辐射及高度仅10mrn、宽度仅13mm的小型化设计．实验结果表明，该天线在其3个工作频段内的回波损耗小于-10dB，实现了H面全向辐射，适合在移动环境中使用．

六频段4G手机天线设计

设计了一款应用于4G手机终端新型六频段天线。采用倒L型、U型、S型辐射枝节获得多频特性;短路加载技术让低于谐振频率的点达到阻抗匹配;耦合馈电方式代替传统的直接馈电以减小阻抗波动,获得较宽频带。该天线尺寸仅占70 mm×16 mm×1.5 mm,能够覆盖手机通信的6个频段:LTE700,CDMA/GSM850,GSM900,DCS1800,PCS1900,WCDMA/UMTS2100。测试结果表明,在工作频段内,散射参数S11≤-6d B,电压驻波比VSWR≤3,均达到工程要求的指标,验证了设计的可行性。

新型圆环嵌套多频印刷天线

提出了一种具有多频特点的新型圆环嵌套印刷天线,该天线由不同直径的圆环嵌套得到。通过电磁仿真软件CST Microwave Studio进行仿真研究,结果表明嵌套圆环的外径、宽度和嵌套数目可以对其通频带中心频率、频带宽度和通频带数目进行控制。设计出了具有2.4 GHz,3.5 GHz,5.2 GHz,5.8 GHz四个通频带的共面波导馈电的单极印刷天线和以平衡微带线馈电的对称振子天线。制作了天线实物并在微波暗室中进行测试,测试结果与仿真吻合较好,该天线具有近似独立的频率可控性和较小的尺寸,可用于WLAN和WiMAX等领域。

六频段手机天线的设计

提出了一种应用在手机终端上,同时能够覆盖无线通信频段中六频段的新型天线设计。在设计中应用到了多个短截线和条带线来产生多频段。整个天线包括接地面在内的体积是38mm×140mm×7mm。该天线能够工作在LTE700、AMPS800、GSM900、ISM/Bluetooth、WLAN和WiMAX这6个频段。根据计算、仿真优化的尺寸,对天线原型进行了制作与测试,在最后给出了软件仿真结果和实际测试结果,结果显示两者基本吻合。

一种小型化五频段可重构蝶形天线的设计

提出了一种新型多频段可重构天线.该天线采用小型平面蝶形结构,尺寸为35.0mm×38.0mm×1.6mm,由U型馈电带线、矩形寄生单元和接地面构成.通过调节馈电带线的长度和选择寄生单元,改变天线的局部结构和表面电流分布,从而获得不同的工作频段.该天线可在1.94～2.22GHz、2.32～2.54GHz、3.08～3.78GHz、3.63～4.83GHz、4.82～6.85GHz五种频段之间实现可重构,覆盖了主要的无线通信系统工作频段,各个状态具有良好的全向辐射特性和较高增益.因此,具有较大的实用价值.