Compact Coplanar Epsilon-Negative Antenna with Ultra-Wide Band Character

In this paper, a compact coplanar epsilon.negative(ENG) antenna is proposed with ultra.wide operation band and small size of 18×11.5 mm2. The proposed antenna is designed based on a coplanar.waveguide(CPW) feeding antenna, and thus the via.free structure is employed to realize the ENG unit cell, which is convenient to tune the frequency of zeroth.order resonance(ZOR) and extends the ZOR bandwidth. The high.order resonant frequencies are achieved and mainly determined by the separate slots that are located between the radiating patch and the ground plane. Adding the left.handed inductance between the radiating patch and ground has slight impact on the high.order resonant frequencies, and then the ultra.wide band is achieved by merging the ZOR bandwidth with the high.order resonant bandwidths. The ground plane primarily works as a matching network for the proposed antenna. Although it generates a low.frequency resonance, the performance is undesirable due to the impedance mismatching. The measured results show that the reflection coefficient, |S11| <.10 d B, is in a wide frequency range from 5.25 to 13 GHz, which covers the upper operation band of UWB communication. Also, the antenna contains relatively stable gains and omni.directional radiation patterns.

Design of Integrated Triple Band Notched for Ultra-Wide Band Microstrip Antenna

Ultra-wideband (UWB) is one of the recent topics that received a great concern from academia and industry. However, UWB found many difficulties to be standardized due to the overlay working that made UWB an important potential interference source to many licensed and unlicensed spectrum throughout the band 3.1 to 10.6 GHz. This paper demonstrates the design of integrated triple band notched for UWB Microstrip antenna. We simulated UWB short range systems which require low power and these are built using inexpensive digital components. We proposed a compact triple band notched CPW (Co-planar Waveguide) fed Micro strip Antenna (MSA) for UWB. This band-notched antenna has rejection characteristics at 3.2 GHz (for Wi-MAX band 3.16 to 3.32 GHz), at 5.5 GHz (for WLAN 2 band—5.3 to 5.72 GHz) and at 7.9 GHz (for ITU band 7.72 GHz to 8.13 GHz). The simulation was done using IE3D simulator.

Novel Compact UWB Band Notch Antenna Design for Body-Centric Communications

This research analyzes and implements an innovative and tiny ultrawideband(UWB)antenna with band-notched features for body-centric communication.The shape of the designed antenna looks like a‘swan’with a slotted patch.Computer Simulation Technology(CST)is used to assess and investigate the performance of this antenna.With a band notch,this antenna can prevent interference from Wireless Local Area Network(WLAN)(5.15–5.825 GHz)and Worldwide Interoperability for Microwave Access(WiMAX)(5.25–5.85 GHz)systems.At first,the performance parameters like return loss response,gain,radiation patterns,and radiation efficiency of this UWB antenna are evaluated.After that,the human body effects on the antenna performance of the antenna are also examined to place the antenna at various distances away from 3-layers of phantom body model at different frequencies.All the on-body performance parameter results are compared and analyzed with free space performance parameter results.Lastly,by changing patch slot length and ground plane length,parametric studies were done for performance comparison.According to this research,it is noticed that the antenna is tiny and new.It shows good performance in body case as well.Hence,the antenna is very suitable for healthcare applications.

Design and Analysis of a Compact Band Notch UWB Antenna for Body Area Network

This paper presents the design of a small printed ultra wideband antenna with Band Notched characteristics. Both the free space and on-body performances of this antenna were investigated through simulation. The newly designed UWB antenna is more revised small form factor sized, with the ability to avoid interference caused by WLAN (5.15 - 5.825 GHz) and WiMAX (5.25 - 5.85 GHz) systems with a band notch. The return loss response, gain, radiation pattern on free space of the antenna were investigated. After that, the on-body performances were tested on 3-layer human body model with radiation pattern, gain, return loss, and efficiency at 3.5, 5.7, 8, 10 GHz and all the results were compared with free space results. As the on-body performance was very good, the proposed antenna will be suitable to be used for multi-purpose medical applications and sports performance monitoring.

Optimization of band-notched UWB antenna using micro-genetic algorithm combined with FDTD

The micro-genetic algorithm (MGA) optimization combined with the finite-difference time-domain (FDTD) method is applied to design a band-notched ultra wide-band (UWB) antenna. A U-type slot on a stepped U-type UWB monopole is used to obtain the band-notched characteristic for 5 GHz wireless local area network (WLAN) band. The measured results show that voltage standing wave ration (VSWR) less than 2 covers 3.1-10.6 GHz operating band and VSWR more than 2 is within 5.150-5.825 GHz notched one with the highest value of 5.6. Agreement among the calculated, HFSS simulated and measured results validates the effiectiveness of this MGA-FDTD method, which is efficient for UWB antennas design.

A Novel Bow-Tie Antenna with Triple Band-Notched Characteristics for UWB Applications

This paper presents the design of a compact bow-tie antenna with triple band notched characteristics for UWB applications. The proposed antenna can operate from 3.1 to 10.6 GHz with VSWR - 8.4 GHz) centered at 8.1 GHz, the CSRR2 rejects the WLAN band (5.15 - 5.85 GHz) centered at 5.6 GHz, and the CSRR3 rejects the band (4.10 - 4.47 GHz) centered at 4.32 GHz. Compared with recent design, this antenna is more compact, and presents better simulation results of its characteristics. Our newly designed antenna is a potential candidate for application in UWB communication systems.

A Directional Differential-Fed UWB Antenna with Stable Radiation Pattern

A directional ultra-wideband(UWB)antenna with improved radiation patterns is presented.The proposed sheme comprises a differential-fed microstrip antenna and a rectangular cavity.The hexagon-shaped slot and four triangle-cut corners on the ground plane of the planar antenna are used to improve the impedance matching within the UWB frequency range.A rectangular cavity is used as the reflector for the planar microstrip antenna,so as to achieve directed radiation.The measured results indicate that the designed antenna exhibits a stable broadside directional radiation patterns within the entire operating frequency band.Furthermore,thanks to the differentially driven technique,the cross-polarization is greatly decreased and the polarization purity is maintained in a high level.

基于MOEA/D算法的三陷波超宽带天线设计

为实现超宽带通信中对WIMAX(3.3~3.7 GHz)、WLAN(5.150~5.825 GHz)和ITU(8.01~8.50 GHz)频段干扰的抑制,提出了一种基于MOEA/D算法优化设计的具有三陷波特性的超宽带天线。天线采用T形结构作为辐射贴片,通过改变贴片形状等方法实现在3~12 GHz的超宽带。在辐射贴片上刻蚀两个U形缝隙和在传输线两侧加载C形开口环,对天线进行陷波设计。利用MOEA/D算法对陷波结构的结构参数和加载位置进行优化,实现了在3.31~3.69 GHz、5.25~6.13 GHz和8.01~8.51 GHz频段的陷波效果,成功抑制了频段干扰。与传统扫频优化的设计方法相比,采用MOEA/D算法设计的天线在陷波频带内增益低至-19 dB,各陷波频带准确度误差均在3.6%以下,提高了天线的设计效率,具有一定的工程应用价值。

高保真度超高频局放检测天线研究

设计了一款用于超高频局放检测的超宽带椭圆缝隙天线.该天线具有时域保真度高、尺寸较小、馈电简单等特点.测试结果表明,天线在300~1500 MHz频段内的回波损耗低于-10 dB,平均等效高度15.7 mm,满足局放检测天线的指标要求.通过CST Microwave Studio软件对其时域波形保真度进行仿真计算分析,对局放检测时天线的摆放方向提供参考.结果表明,椭圆缝隙天线在一些角度上的保真度超过0.9,能较好地还原局部放电波形,同时天线较小的尺寸也能更好地适应局部放电现场检测.

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、1000 MHz且带宽为200~1500 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1000 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。

基于模拟退火算法的超宽带天线优化设计

天线在无线通信系统中起着重要的作用,超宽带(UWB)天线更是天线设计中的一种重要方式。针对UWB天线,可以通过模拟退火算法对其进行优化设计,该算法在精度和收敛速度方面有着较高的优点,能够优化UWB天线的性能,有效地减小电磁干扰。仿真结果表明:在2.05 GHz处时,S11小于-10 dB;在3.45 GHz时,S11小于-25 dB,在此频带,入射功率将以大于90%的效率被天线进行发射。同时,UWB天线的带宽覆盖基本在2.00~3.50 GHz的频段中,结果基本符合覆盖频段的要求;在2.45 GHz的工作频带中,仿真的增益结果为6.62 dBi,在YZ轴平面增益效果良好。经过模拟退火算法优化后的UWB天线,入射功率有了较大的提升,且符合覆盖频段的要求,信号保真效果良好。

介质杆天线的时域特性分析

超宽带技术在通信、雷达等众多领域获得广泛应用,时域天线是其关键技术。对介质杆天线用作时城天线的可行性进行了分析,并给出选择介质杆参数的依据。同时还使用FD-TD(时域有限差分法)数值计算方法分析了在超宽带情况下介质杆的直径、激励方式及终端渐变方式对天线的传播特性及辐射特性的影响。分析表明这种天线适宜用作时域天线。

高功率超宽带脉冲辐射实验装置研制

研制了高功率超宽带脉冲辐射实验装置。该装置主要由脉冲充电电源、超宽带脉冲产生装置、超宽带脉冲发射天线三部分组成。达到的主要指标为:脉冲电源输出电压600 kV、重复频率100 Hz;脉冲压缩输出峰值功率约10 GW、脉宽1.2 ns;在辐射天线轴上220 m处,辐射峰值电场16.1 kV/m、等效辐射功率0.42×1012W;辐射场E面方向图半功率宽度为8°,H面方向图半功率宽度为9°。

一种可控三陷波超宽带天线设计与研究

为了避免如Wi Max,WLAN和X频段卫星系统等窄带通信系统对超宽带通信系统的影响,该文提出一种具有可控三陷波特性的超宽带天线。该天线通过在辐射贴片和接地板上开槽,并在基板背面增加环形寄生单元的方法实现三陷波特性。天线在3.1-10.6 GHz的超宽带频段内能够有效地工作并抑制3种不同的窄带通信系统的干扰。同时在环形寄生单元处增加开关设置,使天线能够实现双/三陷波的功能切换,并增强陷波性能。实测和仿真结果吻合,该天线实现了良好的陷波功能,在工作频段内有良好的辐射方向特性。

超宽带天线口径辐射效应的时域研究

如何高效而又有较少拖尾地将信号辐射出去是超宽带天线的设计关键 ,本文利用FDTD方法研究了在口径面上设定场值的情况下口径形状和激励脉冲的脉宽与辐射波形之间的关系 ,得出在不同口径形状的情况下口径辐射的两个主轴面的辐射情况。

箭形共面波导超宽带天线的设计

利用单极子结构和共面波导特性设计了一种小型化超宽带箭形单极子天线。该天线带宽达到3.9~10.9GHz。使用三维电磁仿真软件HFSS12对天线进行仿真并进行优化,得到回波损耗、电压驻波比,增益等参数,其中回波损耗在3.9-10.9 GHz小于–10 dB,电压驻波比小于2。仿真结果表明该天线符合设计要求,在整个带宽频率范围内具有较稳定的增益和辐射方向性,其可广泛应用于商业超宽带无线通信领域中。

一种新颖的树状分形超宽带天线

该文设计一种新颖的树状分形超宽带天线,该天线采用梯形结构的有限接地面。增加树状分形结构的迭代次数和优化有限接地面的形状可以使天线获得良好的阻抗匹配,进而实现天线的超宽带性能。该天线的工作频带为4.2~17.5 GHz（相对带宽为122.6%）,天线的电尺寸为0.35l′0.35l,可应用于C波段、X波段、Ku波段和超宽带（UWB）波段通信,具有广泛的应用前景。实测结果和仿真结果吻合,证明了该天线的有效性。

一种用于高速公路探地雷达的新型时域超宽带TEM喇叭天线

基于传输线理论和阻抗渐变思想,采用指数渐变结构及加载技术,对应用于高速公路探地雷达的超宽带TEM喇叭天线进行了设计和优化,分析了不同延展面条件下的驻波特性,应用金属反射腔和分布式电阻加载,进一步改善天线性能,并根据最佳仿真结果制作了一副天线。天线的测试结果表明:该TEM喇叭天线在0.9–12.6 GHz的带宽内电压驻波比小于2,波形保真性好。应用于高速公路探地雷达,取得了较好的效果。

基于SRR结构的陷波超宽带天线设计

针对超宽带系统易受窄带信号干扰的问题，设计了一种新颖的基于金属开口谐振环（SRR）结构的平面超宽带陷波天线。在天线的辐射贴片上加载U形缝隙，实现了其陷波特性。利用仿真软件研究了U形缝隙的物理尺寸对其陷波特性的影响，并对所设计的超宽带天线进行了制作和测量。结果表明，所制天线在超宽带系统3．1～10．6GHz工作频段的电压驻波比（VSWR）小于2，在WLAN频段具有良好的陷波特性，有效地抑制了超宽带通信系统与窄带通信系统之间潜在的干扰。

生物医用冲激脉冲辐射聚焦天线的设计与优化

ps级电场脉冲的宽度远小于生物组织的细胞核膜与细胞膜的充电时间常数(几十纳秒和几百纳秒),且具有丰富的超宽带频谱(几乎从直流到GHz),因而具有很高的时间分辨率和空间分辨率。文章提出一种由同轴TEM馈电的圆锥结构与椭球面反射器组成的超宽带冲激脉冲辐射天线,通过冲激脉冲辐射天线将高强度皮秒电场脉冲传输至生物组织浅层靶点位置形成有效的聚焦。仿真分析了4种模型在不同条件下聚焦区域的电场分布,并对天线结构进行了优化选择。结果显示该天线在焦点区域的电场分布保持了输入脉冲的冲激特性,电压驻波比小于2,且具有稳定的增益和场方向图,x轴方向电场分布的半峰带宽小于20mm,y轴和z轴方向小于10mm。