单层超宽带微带贴片天线的设计与分析

该文提出了一种新颖超宽带微带天线。该天线由微带宽槽天线的基本结构变形而来,其结构由矩形馈电微带贴片与矩形宽槽孔贴片组成。矩形宽槽孔开在金属GND板上,而矩形馈电贴片在介质板的另一面并在矩形宽槽孔框内偏下方。贴片与馈电线对接处采用渐变结构来达到阻抗匹配。以矩形宽槽尺寸为主构成了低频段的等效谐振电长度,而馈电贴片尺寸构成了高频段的等效谐振电长度。在各自的谐振频区上,矩形宽槽与馈电微带贴片两者相互耦合,构成两谐振电长度的天线叠合组成为一共面天线,从而拓展了天线的带宽。该文运用HFSS仿真软件,根据设定尺寸进行了仿真设计,制备了两只不同频段的样品天线。仿真结果和实验结果基本一致,表明该原理设计出的天线可实现超宽带特性。     

宽频带缝隙馈电双层贴片微带天线设计

采用矩形谐振缝隙耦合馈电的方式,在辐射贴片的上方引入寄生矩形谐振器,地板下方四分之一波长处放置反射面,两辐射贴片之间使用多层低介电常数的泡沫介质基板,设计了一款宽频带微带天线。该天线不仅频带宽,后向辐射小,而且结构简单,便于阵列集成。仿真结果表明:在电压驻波比(VSWR)小于等于2时,该天线的阻抗带宽度达到了中心频率的58.42%;在5.12~8.98 GHz的频率范围内,天线的增益大于7.1 dB,回波损耗小于-10 dB。     

双频微带天线设计

基于微带贴片天线在无线引信中的应用,根据微带天线原理,通过HFSS天线仿真软件,设计了中心频率为6.14GHz和7.2GHz的同轴馈电圆形微带天线。仿真结果表明:该天线谐振频率、回波损耗等性能参数符合设计要求。     

宽频带高增益RFID微带天线阵设计

设计了一种宽频带高增益微带天线单元并组成了4元阵列。通过在普通矩形微带贴片加载2个对称切角、改变贴片表面电流分布实现天线单元的双频工作,调节切角尺寸使两个频点相互靠近融合,展宽频带。在此基础上确定合适的阵元间距,采用等副同向并联馈电,馈电网络由T型结功分器组成,并使用同轴探针馈电方式,实现天线阵列的设计。通过高频电磁结构仿真软件HFSS对天线进行仿真和优化,结果表明阵列天线性能良好。     

树枝状结构超材料在微带天线上的应用仿真

针对普通微带天线增益低、方向性差的缺点,提出一种树枝状结构超材料微带天线模型,为提高性能,利用以有限积分为主的CST软件对树枝状结构负磁导率微带天线模型和树枝状结构左手材料覆层微带天线模型进行了仿真研究。仿真结果表明,相对于普通微带天线,负磁导率材料基板天线增益提高了,并使有效辐射功率得到提高。同时,树枝状结构左手材料覆层天线的增益提高了1.2dB,相当于天线的有效辐射功率提高了31.8%,E面和H面主瓣半功率波束宽度分别收缩了45.8°和44.8°。树枝状结构负磁导率材料和左手材料可以抑制天线激发的表面波,对天线发射的电磁波进行会聚效率更高。新型天线可用于导弹、卫星及飞机飞行器等。     

一种易调谐的小型GPS微带天线设计

提出了一款新颖的易调谐小型GPS微带天线结构。采用正方形贴片作为辐射单元,通过切角微扰实现右旋圆极化辐射;在贴片中心开槽和四周开缝,利用贴片曲流技术减小天线的尺寸;使用同轴中心馈电加载微带匹配段,实现阻抗的匹配。文章给出了天线的设计思路,并进行了大量的电磁仿真优化,最终对天线进行了加工实验。实验结果表明,在设计的频带内,天线具有较好的阻抗匹配和圆极化辐射特性。该天线具有结构紧凑、易于调谐的特点,具有良好的应用前景。     

北斗宽波束“U”型槽双频微带天线的设计

基于北斗导航系统的实际通信需求,要求接收天线具有多频带、宽波束、小型化等特点,为此选定设计一款矩形贴片微带天线。结合微带天线的双频圆极化理论,采用同轴线的馈电方法,设计了一款在贴片上开“U”型槽的双频微带天线,使微带天线可以同时工作在北斗B2频段（1210±10MHz）和B3频段（1268±10MHz）,实现了微带天线的双频化,而且减小了天线尺寸。通过HFSS对该天线进行了仿真和参数优化,结果表明,天线回波损耗S11小于-20dB;天线增益大于3dB;双频内的轴比小于6dB;具有较宽的波束,较好的圆极化性能,较小的尺寸,可达到设计要求;而且,电路的设计方法简单,制作工艺简单,可为实际的应用提供参考。     

基于复合左右手传输线结构的新型微带天线

基于复合左右手传输线结构的零阶谐振理论,提出了一种新型双层结构的微带天线,仿真结果表明该天线具有比单层微带天线更小的尺寸。研究了天线各结构参数对天线特性的影响,并对各参数进行了优化仿真。仿真结果表明该天线具有全向辐射特性,与传统微带天线相比,该天线具有体积小的特点。     

一种矩形微带整流天线的研究与设计

微波整流是无线输电中的一个重要环节,为完成微波能量的接收,设计了一个结构简单、整流效率高的贴片矩形微带整流天线,此整流天线包括矩形微带天线、输入低通滤波器、整流二极管及输出滤波器。该整流天线的面积小,配合其他装置组成的微波输电系统,可方便地应用于传统有线输电无法应用的场合。通过系统仿真以及实验测试,验证了整流天线的可行性及其高效率,实际测量后计算出整流效率高达63．4％。     

电调微带贴片天线CAD

研究了探针馈电变容管加载的微带贴片天线的电特性,结果表明在以未加载微带贴片天线的谐振频率2．2GHz为中心可获得50％的有效阻抗带宽。用最简单的传输线模型估算谐振频率,实验结果与预测相当地一致。     

基于同向开口双环的双通带左手材料研究

为了改进传统的开口谐振环-导线（ SRRs-wire）结构电磁特性,利用不同大小的开口谐振环所产生不同负磁谐振频率点的特点,设计了同向开口双环的SRRs-wire结构,并给出了其等效电磁参数反演结果。通过增加其单元结构的金属短线的个数实现了双通带左手特性;同时通过改变外环为U型环降低了内外环的相互耦合。利用内外谐振环间具有弱耦合的特性,提高了高频左手通带的带宽,同时可以较方便地调节双通带工作频率点,具有很好的可调性。     

Design of a 16‐beam pattern‐reconfigurable antenna for vehicular environment

This article presents the design of a multipattern antenna with pattern switching for vehicular communications. The proposed antenna has four triangular patches integrated onto a split square ring (SR) resonator to operate at two distinct frequencies, viz. 2.4 and 3.5 GHz. The proposed antenna is designed with a view to enhancing the link reliability of Wireless Local Area Network (WLAN), WiMax, and vehicle to vehicle communication frequencies. Each triangular patch is separately excited using a microstrip line feed to enable beam steering. The ground plane of the antenna is embedded with two SR slots to improve the bandwidth and radiation performance. Further gain enhancement is achieved by loading the antenna with a plane reflector located at a distance of 20 mm from the antenna's ground surface. In reality, this reflector is realized using the vehicle's roof which provides gain enhancement up to 5.2 dBi at 2.4 GHz and 4 dBi at 3.5 GHz. By exciting single to multiple ports sequentially 16 different radiation patterns are obtained, which provides high‐gain omnidirectional coverage. The prototype antenna is fabricated and the simulation results are verified using experimental measurements. From the results, it is evident that the proposed antenna is suitable for vehicular communication applications.     

CPW fed miniaturized dual‐band short‐ended metamaterial antenna using modified split‐ring resonator for wireless application

A miniaturized dual‐band metamaterial (MTM) antenna has been designed in this article. The designed coplanar waveguide fed antenna has composed of inner split‐ring resonator and an outer open ring resonator with rectangular stub. The series parameter of the antenna is used to determine the zeroth order resonance frequency due to short‐ended boundary condition. The whole size of proposed structure is 20 × 25.5 mm². This MTM antenna exhibits dual‐band operation at 3.17 GHz (3.1–3.22 GHz) and 5.39 GHz (5.27–5.47 GHz). The proposed MTM structure achieves measured peak gain of 0.71 and 1.89 dB at 3.17 and 5.39 GHz, respectively. The proposed antenna can be used for recent radio communication in form of S‐band application and Wi‐MAX.     

Compact size flexible UHF RFID tag antenna for racing pigeon ring applications

A very small size radio frequency identification (RFID) tag antenna specifically designed for racing pigeon ring applications is proposed. The structure of this UHF tag is a closed‐loop type printed on a 30 × 8 mm² polyimide film of thickness 0.063 mm. Thus, it can be wrapped into a double layer plastic cylindrical ring of size similar to those used for racing pigeon. By simply tuning the inner width of the loop, good conjugate matching between the tag chip input impedance and the tag antenna can be achieved. When mounted onto a real preserved dried pigeon feet specimen, the measured impedance bandwidth of the tag antenna was 901‐929 MHz. Further experimental results have also shown that the proposed antenna has a maximum reading range of up to 50 cm.     

A low profile dual band resonant cavity antenna

A low profile dual band resonant cavity antenna that incorporates double sided partially reflective surface (PRS) with complementary layers is presented here. The PRS is formed by printing periodic array of complementary metallic square loops on the opposite sides of the dielectric material. The PRS has been used as a superstrate, placed above the radiating microstrip patch. This PRS acts as a dual band matching section between the microstrip patch and free space, hence resulting in dual resonance. The proposed structure has been analyzed using equivalent circuit model. Parametric analysis of the sensitive structural parameters has also been discussed. To validate the design, the simulation analysis and experimental results obtained from a prototype operating at 8.9 and 9.4 GHz are presented. The measured gain at the two frequencies is 10.2 and 8.5 dBi, respectively. The overall size of the antenna is 1.78λ × 1.78λ × 0.09 λ with λ corresponding to 8.9 GHz.     

一种新型套筒天线宽频特性的HFSS仿真分析

针对传统套简单极子天线结构变量复杂、要做到3:1的频带宽度难的问题,利用电抗补偿方法设计了一款位于特殊接地铜管上的双层套筒偶极子天线,并利用HFSS软件对结构进行仿真分析,找到影响频带及反射特性的结构参数,通过软件自带的优化功能,对各个参数进行仿真优化,得到工作在800-960MHz,1710-1920MHz,2400-2483MHz频带范围内驻波系数低于1.5的实用套筒天线结构,包含目前移动通信所用频带:2G、3G和WLAN.天线在同一个结构上实现多频工作,且在各个频段内反射很小,节省了天线资源,利于系统集成.     

High‐gain waveguide slot antenna using simple parasitic patch's cover

In this article, a way based on using miniature patch cells has been proposed to increase gain and bandwidth of the waveguide slot antenna. In the presented approach, an array of 3 × 3 metal patches has been used as superstrate to create Fabry Perot theorem resonance cavity. The proposed high ‐ gain and simple antenna is composed of a conventional waveguide slot antenna with an extended broad wall, and an array of parasitic patches which are symmetrically placed over slot at a distance of about free ‐ space half wavelength. The slot has been created on a rectangular waveguide WR90 with 22.86 mm × 10.16 mm × 52.5 mm dimension, also extended wall dimension is 2λ₀ (67.5 mm) × 3λ₀ (107 mm). It has been shown that the proposed structure compared with the conventional waveguide slot antenna improves antenna peak gain from 6.5 to 16.5 dBi and, in the same time, antenna bandwidth from 11% to around 16.2%. More important advantage of the proposed antenna is that unlike to other Fabry Perot antenna with the same gain, there is not any dielectric material in the proposed structure. A prototype antenna was simulated, fabricated, and measured for verification.     

用双负材料改善微带天线阻抗带宽

针对微带天线带宽较窄的问题,采用基于有限元法的HFSS软件,设计1种以双负材料为衬底的微带天线．仿真计算其反射系数,并给出测试结果．对仿真与测试结果进行比较分析表明,相对于同样尺寸以普通材料为衬底的微带天线,以双负材料为衬底的微带天线的带宽展宽约为50％,在中心频率的相对带宽也达到16．6％．