共面波导馈电超宽带天线研究

设计了一种刻蚀在单层覆铜介质基板上的共面波导馈电超宽带天线。所用介质基板由相对介电常数为2.65的聚四氟乙烯制成,尺寸为35.0 mm×35.0 mm×1.6 mm。利用仿真软件HFSS对该天线的参数进行了仿真和优化,并根据优化参数进行了实物天线的制作和性能测试。结果表明,通过在共面波导地面上刻蚀非对称结构的多边形槽,可使天线的频带宽度达到2.2~8.0 GHz(S11<–10 dB),相对带宽达到114%。该天线具有良好的方向图和增益性能,满足超宽带天线的性能要求。     

一种共面波导馈电的双陷波渐变槽天线

为了滤除WIMAX(3.3～3.8 GHz)和WLAN(5.125～5.825 GHz)窄带信号对超宽带系统的干扰,该文提出一款共面波导馈电的小型化双陷波渐变槽天线。共面波导结构可以有效地扩展天线的带宽,实现对整个UWB(3.1～10.6 GHz)频段的全覆盖。通过在天线的馈线上开L型缝隙和在辐射贴片上开一对E字型缝隙的方法,有效实现了在3.15～3.97 GHz和4.94～6.05 GHz频段的双陷波特性,能够抑制WIMAX和WLAN对超宽带系统的干扰。该天线结构简单紧凑,尺寸非常小,仅为40 mm×18 mm×0.813 mm。仿真和实测结果表明该天线在超宽带波段内具有良好的陷波特性、增益特性,可以应用于小型化超宽带系统中。文中方法对于陷波渐变槽天线的研究具有一定的借鉴意义。     

紧凑型共面波导馈电的超宽带印刷天线设计

针对超宽带天线设计的重要性,基于微带天线和电磁散射理论,设计和分析了一种新的紧凑型共面波导反馈超宽带印刷天线。天线采用逆L型和U型非对称的辐射单元结构,以便最大程度地展宽天线带宽。与以往所提出的共面波导馈电天线相比,该天线具有尺寸小、近线性阻抗、高增益、宽频带、准全向性辐射模式和低成本等特点。并且,该天线的主要性能参数达到了一个较好的平衡。仿真和测量结果保持一致。该天线能满足多种宽带无线通信应用的要求。     

共面波导馈电的超宽带天线的研究

本文设计一种共面波导馈电的超宽带天线（UWB）,其阻抗带宽达到341%。所设计的天线印刷在尺寸为28×21×1.6mm3,介电常数为2.65的聚四氟乙烯介质基板上。并利用电磁仿真软件HFSS对影响天线性能的主要物理参数进行仿真、分析和优化,得到天线的理想尺寸。最后,对优化的超宽带天线进行制作,测试。实验结果表明,该天线比传统微带贴 片天线性能有了较大的提高,从而证明利用共面波导馈电的超宽带天线设计方法,能够实现兼容多种通信系统的可行性和有效性。     

新型共面波导馈电超宽带单极子天线设计

提出了一种新型的超宽带单极子天线,该天线将经典圆形单极子的下半圆用两个倒梯形替代,有效减小了天线的体积,利用电磁场仿真软件Ansoft HFSS对该天线进行了仿真优化。结果表明,该天线的阻抗带宽为2.48~15.23 GHz,覆盖了超宽带通信系统的带宽。该天线在2.48~15.23 GHz带宽内的S11≤–10 d B,VSWR≤2,具有比较稳定的辐射特性,符合超宽带通信系统的要求。     

小型双陷波共面波导馈电超宽带天线仿真分析

提出了一种结构简单具有双陷波特性的多用途共面波导馈电超宽带天线。在天线中嵌入了一种缝隙获得了双陷波特性。通过数值仿真对天线的阻抗特性、方向图和增益进行了研究。结果显示该天线在2.9～12GHz的频段内驻波比小于2.2,其中的3.55～3.67GHz及5.58～6.00GHz的范围内具有陷波特性。     

一种共面波导馈电的三阻带超宽带天线设计与研究

设计了一种共面波导馈电的超宽带天线(UWB),该天线的辐射体和地板分别由具有渐变结构的类圆辐射贴片和梯形组成,具有良好的宽带阻抗匹配特性。通过在贴片的不同位置上嵌入3种不同形状的缝隙,实现了天线的3陷波特性。并利用HFSS 12软件对所设计的天线进行仿真测试,仿真计算和实测结果表明,该天线在WiMax(3.3～3.7G)、Wlan(5.15～5.825GHz)以及ITU(8.025～8.4GHz)3个频段内具有良好的陷波特性,并且该天线在其它通带频段具有良好的辐射特性和稳定的增益。天线的尺寸仅有25mm×29mm×1mm,利于与微波器件的集成。     

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。     

应用于超宽带的小尺寸宽带共面波导馈电分形天线

超宽带技术需要小尺寸、宽带宽和良好全向辐射图的天线，因此提出了一种紧凑型非对称共面波导馈电阶梯状超宽带分形天线，利用Ｈ形辐射体、改进馈线结构、非对称馈电和开槽接地板技术实现了4.56ＧＨｚ~13.10ＧＨｚ的阻抗带宽，在工 作频带内所有频率点的Ｈ平面上实现了全向辐射方向图，Ｅ面方向图在较低频率时是双向的并在较高频率时转变为定向的，此外，针对３种不同的基底材料对所设计天线结构进行了分析，实验结果验证了所设计天线结构的适用性，与其他天线相比，该天线结构的平均增益为2.84ｄＢ，尺寸较小且带宽更高。     

一种新颖小型共面波导馈电的超宽带天线设计

设计了一种新颖小型共面波导馈电的喇叭形超宽带天线,接地面不同于传统矩形而采用接地面围绕辐射体两侧向顶部延伸的方式,并且靠近馈线的接地面使用两阶阶梯凹槽,利用仿真软件仿真优化辐射体和接地面的结构参数,天线加工后的尺寸为27 mm×30 mm×1.6 mm,实测阻抗带宽为2.5～12.0 GHz,在3.1～10.6 GHz范围内基本呈全向性,并且具有较稳定的增益,约为2.5 ～ 6.0 dBi.     

Microstrip antennas fed by conductor backed coplanar waveguides

A microstrip antenna fed by a conductor backed coplanar waveguide is demonstrated. The addition of a back-side metallic ground plane involves a possible power leakage owing to the excitation of parallel plate modes (PPMs). A theoretical model, based on the solution of coupled integral equations, is validated by experimental results. It is shown that the power leakage can be avoided by a proper choice of substrate characteristics     

Spline-based geometry for printed monopole antennas

A novel Bezier spline-based geometry for printed monopole antennas is presented. Quadratic curves are used to describe the outline of the radiating element. The geometry is optimised by a genetic algorithm. A small number of control points are used to define the geometry, ensuring a small search space for the GA. The resulting antenna has an impedance bandwidth from 1.44 to 14.7 GHz     

Time-domain characteristics of ultra-wideband tapered loop antennas

Presented are the transient characteristics of a tapered loop antenna fed by the composite right/left-handed coplanar waveguide-to-coplanar stripline balun. The antenna operates within 2.5-7.5 GHz and thus is suitable for ultra-wideband applications. The performance of the system comprising two identical tapered loop antennas is characterised by pulse radiation and reception. The fidelity of pulse response is presented to evaluate the signal distortion in the time domain     

Circularly polarised printed antenna fed by coplanar waveguide

A new structure of the circularly polarised printed antenna fed by coplanar waveguide (CPW) is proposed. FDTD analysis predicts the radiation of the circularly polarised wave from the antenna. The validity of this analysis is established by comparing with experimental results     

Slot-array antennas fed by coplanar waveguide for millimeter-waveradiation

Slot-array antennas with parasitic slots, slot-array antennas fed by coplanar waveguide (CPW), and two-dimensional slot-array antennas fed by CPW were fabricated on fused quartz substrates, and the receiving properties of the antennas were investigated at 94 GHz with the goal of increasing the power gain of the slot antennas. It was found that the power gain of the slot antenna could be increased by 11 dB over a single-slot antenna by using a two-dimensional (8×3) slot-array antenna fed by CPW. It was confirmed that the improvement of the power gain was caused by decreasing surface-wave power in the substrate and by sharpening antenna patterns perpendicular to the substrate     

Dual-polarization slot-coupled printed antennas fed by stripline

This article presents recent techniques in the field of dual-polarization printed antennas for designing shielded radiating structures with high-quality performances in terms of cross-polarization level and input-port isolation. The use of gridded patches provides a natural solution to filtering surface currents and is of key importance in limiting inter-element coupling in arrays. Experimental results obtained on various designs are presented     

Compact printed ultra-wideband monopole antenna with dual band-notched characteristics

A compact printed ultra-wideband (UWB) monopole antenna with dual band-notched characteristics is presented. One complementary split-ring resonator (CSRR) is etched inside the patch of the monopole antenna to achieve dual notch frequency bands. A practical example for a UWB antenna (working from 2.90 to 12 GHz) is demonstrated, with one notch frequency band at 3.40-3.48 GHz and the other at 5.40-5.98 GHz. In addition, the effect of the dimensions of the CSRR on the dual notch frequency bands is also analysed.     

Compact printed ultra-wideband monopole antenna with dual band-notch characteristic

A compact ultra-wideband microstrip-fed planar antenna with dual band-notch characteristic is presented. Two notched frequency bands are achieved by embedding an E-slot in the radiation patch and a U-slot defected ground structure in the feeding line. Moreover, the two notched bands can be controlled by adjusting the length of the corresponding slot. Experimental results show that the proposed antenna, with compact size of 35 x 14 mm, has an impedance bandwidth of 2.87-10.91 GHz for a voltage standing-wave ratio less than 2, except two frequency notched bands of 3.49-4.12 and 5.66-6.43 GHz.     

Optimized basis functions for slot antennas excited by coplanar waveguides

A method is proposed for the analysis of slot antennas excited by coplanar waveguides. First, a standard integral equation for the continuity of the magnetic field is formulated. Then the appropriate equivalent magnetic currents of the method of moments are represented in terms of entire-domain basis functions which synthesize the resonant behavior of the slot and the field in proximity of the feeding source and of the bends. In order to define these basis functions, canonical geometries are identified, whose Green's functions have been found analytically. The accuracy and the effectiveness of the method in terms of convergence rate and number of unknowns is demonstrated by comparison with a standard fine meshing full-wave analysis.