一种超宽带印刷单极天线的研究

提出并研究了一种平面印刷单极天线,采用共面波导馈电,天线辐射体采用椭圆和带有对称枝节环的组合结构。着重研究如何通过调整内、外圆环枝节的长度,改变天线的谐振特性,从而实现天线在3.1～10.6GHz频率范围内回波损耗S11<-10dB,满足超宽带通信的要求。制作了实验模型,用矢量网络分析仪进行测试,与仿真结果比较取得较好一致性。     

一种改进的小型超宽带天线

为了有效地对超宽带天线进行小型化,通过对平面椭圆单极子超宽带天线进行切半和切边处理,设计了尺寸为10mm×17mm的小型超宽带天线。为了改善因对天线进行切半而恶化的全向辐射特性,在小型超宽带天线的辐射体中引入了缝隙结构。仿真结果表明:改进的小型超宽带天线在整个超宽带频带内具有良好的阻抗匹配和全向辐射特性。该天线的测量结果与仿真结果基本吻合。     

一种新型具有带阻特性的超宽带天线

提出了一种新型共面波导馈电的,具有带阻特性的平面单极子超宽带天线.为了抑制与WLAN系统的干扰,通过在天线平面上加入调谐支节,从而达到了在WLAN频段上的带阻特性.该天线在回波损耗S11≤-10 dB的工作频带带宽达到了2.49～14.53 GHz,并且在4.9～5.92 GHz频带内形成了阻带.采用基于有限元的电磁场仿真软件HFSS进行了优化,并绘出天线的方向图,结果表明该设计方法的有效性.     

一种超宽带贴片天线的设计与研究

随着无线通信和雷达系统的不断完善发展,对天线性能提出了体积小、重量轻、制作简单和宽频带等特性要求,超宽带天线技术应运而生。通过介绍超宽带贴片天线的技术特性、研究现状及趋势,提出了一种特有的超宽带贴片天线设计方案。简要介绍了Ansoft HFSS仿真软件,且用其对回波损耗和远场辐射图进行仿真及优化设计,使得设计的天线的带宽大致在1.50~11.50GHz范围内,且在WLAN频段达到了良好的陷波特性,有效地抑制了超宽带通信与窄带通信之间的潜在干扰,实验结果表明该设计满足了超宽带的频带要求。本文网络版地址：http：//www.eepw.com.cn/article/164389.htm     

一种采用组合陷波结构的新型超宽带平面天线

首先提出了一种小型平面超宽带天线的设计。天线采用FR4印刷电路板制作,由共面的叉形辐射单元和多边形缝隙构成,整体尺寸为30 mm×28 mm×0.8 mm。采用HFSS软件对天线进行了优化设计和参数分析。然后,通过在叉形辐射单元增加微带开路枝节并且在地板开一对倒L形细裂缝的办法,设计了组合陷波结构的超宽带天线。实验表明：组合陷波结构天线在51～5.9 GHz阻带内,回波损耗的最大值达-1.5 dB,与常规的单陷波结构超宽带平面天线相比较,其回波损耗频率曲线更为陡峭,从而能更有效地提高超宽带通信系统抑制无线局域网设备所带来干扰的能力。     

一种用于隧道覆盖的超宽带单极子天线

通过分析目前隧道或地铁工程中经常使用的泄漏电缆覆盖成本较高的不足,提出了一种新的设计方案——双向天线覆盖,并且根据平面单极子的辐射特性,采用电磁仿真软件Ansoft HFSS建模仿真,设计并实现了一款在155～1057 GHz频带内具有良好阻抗特性的环形椭圆平面单极子天线,其相对带宽接近150%,水平面辐射方向图是沿着隧道双向分布的,而且实测结果与仿真数据相吻合。该天线结构简单,容易实现,采用壁挂形式,安装方式简单可靠,造价成本低。     

一种采用微带馈电的陷波超宽带天线的设计

提出了一种改进的贴片超宽带天线。所设计的天线的是印刷在35mm＊35mm＊1mm的FR-4介质基板上。采用微带线馈电,通过将传统的矩形贴片改进为多边环形辐射单元,并且为了拓宽宽带特性,在接地板上刻蚀出一个凹形槽,使其满足超宽带系统（3.1～10.6GHz）的带宽要求。同时为了避免无线局域网（WLAN）的干扰,利用开路微带线来使天线具有陷波特性。采用高频结果仿真软件HFSS对天线进行仿真,结果表明该天线在超宽带频带范围内的回波损耗小于-10dB,同时实现了所需频带的陷波特性。     

一种新颖可控陷波特性的超宽带天线

设计了一种具有可控陷波特性的超宽带天线,有效抑制了超宽带通信系统与窄带通信系统之间潜在的干扰。该天线的尺寸仅为3.5 cm×3.5 cm×0.1 cm,使用微带线进行馈电,并通过在天线单元上加载支节,从而实现天线可控陷波特性。利用仿真软件HFSS对天线进行计算,对天线的阻抗、方向图特性进行仿真对比。仿真结果表明,天线在超宽带系统3.1 GHz~25 GHz工作频段内的电压驻波比（VSWR）小于2,在5.2 GHz~5.8 GHz频率范围内的滤波特性较好,有效降低了无线局域网系统对超宽带系统的影响,在工作频段内该天线的辐射方向特性和方向图特性都较为理想。     

超宽带脉冲天线的补偿技术研究

针对超宽带通信系统中脉冲信号传输保真度的问题, 分析了保真度与脉冲天线的相频特性、增益-频率特性的关系, 提出通过调整天线的增益特性来对信号在自由空间产生的传输损耗进行平衡补偿的技术.通过对一款高保真印刷半锥形单极天线(Half-Printed Tapered Monopole Antenna, Half-PTMA)增益-频率特性的仿真分析, 以及将此补偿技术应用到一款超宽带平面单极天线的设计改进, 改进后保真度提高了5%, 验证了文中补偿技术的有效性, 为超宽带脉冲天线的高保真设计提供了有价值的设计依据.     

一种H型极子小型超宽带天线

设计了一款检测用小尺寸平板超宽带天线,天线为单极结构,天线尺寸为15mm×12mm×1mm。天线基板材料为高性能介电材料Taconic,天线采用H型极子结构,可以有效地调整天线回波损耗曲线,天线背部采用开槽结构,开槽尺寸为12mm×10mm。天线带宽为6GHz-7GHz,天线正向辐射增益达到3．3dBi,具有足够的穿透辐射强度,天线基本性能满足超宽带检测领域的应用要求。     

一种便携式微带超宽带天线

改进了一种印刷单极U型微带超宽带天线.利用Ansoft公司的高频仿真软件HFSS对影响其辐射性能的关键参数进行了仿真计算,通过优化使其尺寸减少到原来的22%,阻抗带宽也展宽了24%,最后给出了天线的反射损耗曲线和辐射方向图.天线的-10dB反射损耗的频率覆盖范围为2.3～11.2GHz.这种天线不仅适用于短距离超宽带无线通信,而且也适合于无线局域网(WLAN)与蓝牙(BT)通信.     

A new ultra-wideband fractal monopole antenna

The paper focuses on the peculiar dynamic behaviour of the recently developed 8 mm² TO-220-packaged, high-voltage, double-interdigitated (or rwo interdigi-tation levels—TIL) GTO thyristor. This novel power device was rated under both slightly and heavily inductive resistive loads, i.e. close to the real conditions encountered in practical power circuits employing GTO thyristors. Emphasis is laid on the ability of TIL GTOs to switch safely, with minimum power losses, a certain amount of anode current under high-voltage conditions and high commutation frequencies. The merits of TIL GTO thyristors are analysed in terms of their reliability and switching efficiency, which include the total power losses (conduction and switching losses), turn-on and turn-off gains and the switching speed. It is shown that thanks to their built-in self-protective features, these novel GTOs possess an enhanced current-handling capability at commutation frequencies up to 50kHz under extremely tough load conditions. The main implications of the results for power applications are outlined.     

Coupled-line-fed dual-notch ultra-wideband antenna

A coupled-line-fed ultra-wideband planar antenna with dual band-notched characteristics is proposed. Narrow frequency band notching at 3.5 and 5.5 GHz is achieved using bent resonators coupled to the main feedline. Moreover, the two notched bands can be controlled independently. The proposed antenna design is tested using two independent full-wave solvers.     

Compact band-notched ultra-wideband antenna

A novel band-notched ultra-wideband antenna having small dimensions (12.7 times 22 times 1.6 mm) is proposed. With the use of a modified ground plane, a microstrip feed with bevel, and parallel dual patches, the proposed antenna has very wide impedance bandwidth measured at 8.18 GHz (2.97 to 11.15 GHz, defined by 2:1 VSWR). By inserting slits in the ground plane, a band-notched frequency of 5.12 to 5.88 GHz is achieved. The transmission loss and group delay are measured and discussed.     

Optically transparent ultra-wideband antenna

A novel optically transparent ultra-wideband (UWB) disc monopole antenna is proposed. The antenna is fed by a 50 Ω coplanar waveguide and its operational bandwidth is measured from 1 to 8.5 GHz. Gain and radiation patterns are also presented. The antenna exhibits omnidirectional and monopole-like radiation patterns at low frequencies for the H-plane and E-plane, respectively. The proposed antenna uses the highly conductive AgHT-4 transparent film, which makes the antenna suitable for inter-vehicle communication.     

Compact omnidirectional band-notch ultra-wideband antenna

A novel ultra-wideband printed monopole antenna with a band-notch characteristic and stable omnidirectional radiation is presented. The antenna design adopts a bevelled square patch as a monopole, a double-feed technique and a microstrip feeder embedded with an inverted U-shaped slot. Good agreement between simulation and experiment shows that the proposed antenna achieves an impedance bandwidth of 3.05-5.15 and 6.02-10.84 GHz for VSWRles2, a stable omnidirectional radiation and a low cross-polarisation level.     

Compact coplanar waveguide-fed ultra-wideband antenna

A novel coplanar waveguide fed planar antenna with an extremely broad bandwidth in excess of 128% is presented. This comfortably covers the required bandwidth for ultra-wideband communication applications, and exhibits the required omnidirectional pattern characteristics. The antenna is also very small in size, only 0.3 lambda square at 3 GHz     

一种高隔离度的三阻带超宽带MI MO天线设计

针对超宽带传输在无线通信系统中的要求,设计了一种以FR4为介质基板的高隔离度三阻带超宽带MIMO(Multiple Input Multiple Output)天线.该天线由两个水平放置的天线单元组成.通过在U型辐射贴片上腐蚀两个C型槽和在馈线两侧增加两个对称的C型枝节阻断了WiMAX、WLAN和7.5 GHz-X波段...     

一种新型的双频段超宽带双极化天线

提出一种集成双频段、双极化、超宽带特性的新型天线。该天线通过双枝节结构形成双频,利用多节阻抗匹配的巴伦馈电、宽缝形式对称U型辐射面结构实现超宽带,并采用介质板±45°正交以及合理馈电和交叉位置布局形成双极化。结果表明,这款天线既可工作在824~960 MHz的全2G通信频段内,又可工作在1.7~2.7 GHz的全3G通信频段内,并且在两个频段内回波损耗≤–14 dB,两端口间带内隔离度≤–30 dB,交叉极化电平≤–20 dB。     

末端开槽超宽带天线的研究

基于常规平面半椭圆偶极天线形式,研究了末端开槽天线的特性,分析了四种不同的末端开槽方式对天线驻波系数、端口阻抗、群延时等特性的影响.在仿真分析比较了天线末端采用半圆面开槽、电阻加载的方式、开槽单元数量以及背腔形式对天线特性影响的基础上,设计了一种中心频率为400 MHz的平面半椭圆、末端双半圆面开槽加载以及V形金属背腔的新型超宽带天线,加工制作并测试了该天线.测试结果表明:该天线阻抗带宽优于两个倍频程,波形保真度高;同时该天线成本低廉易于集成,能够应用于穿墙成像雷达.