A printed monopole ellipzoidal UWB antenna with four band rejection characteristics

An antenna design with four band rejection characteristics for UWB application is demonstrated. The proposed unique UWB antenna has shape of an embedded ellipse at top of trapezoidal patch (named as ellipzoidal), 50 Ω impedance microstrip line feed and a truncated beveled ground plane. To realize four band stop characteristics, three inverted U-shaped and a single I-shaped slots each of half guided wavelength are utilized on radiating element. The fabricated antenna has dimensions of 27 mm × 36 mm × 1.6 mm. This four band notched ellipzoidal UWB antenna has measured frequency bandwidth 2.8–14 GHz for magnitude of S₁₁ < −10 dB level. The measured ellipzoidal antenna exhibits four band rejection characteristics for magnitude of S₁₁ > −10 dB at 3.55 GHz for WiMAX band (3.26–3.9 GHz), 4.55 GHz for ARN band (4.35–5.05 GHz), 5.7 GHz for WLAN band (5.5–6.65 GHz) and 8.8 GHz for ITU-8 band (7.95–9.35 GHz). The proposed ellipzoidal UWB antenna maintains omnidirectional radiation pattern, gain, linear phase response, <1 ns group delay, and transfer function in the whole UWB operating bandwidth except at notched frequency bands.     

A slot resonators based quintuple band-notched Y-shaped planar monopole ultra-wideband antenna

A Y-shaped ultra-wideband (UWB) monopole antenna containing modified ground plane with five stop bands is presented. An inverted U-shaped slot and a C-shaped slot are placed on Y-shaped radiating patch to achieve two notched bands while three pairs of C-shaped slots are placed at different positions on modified ground plane to achieve three more notched bands. The proposed antenna is designed, fabricated and experimentally tested. The designed Y-shaped antenna has overall dimensions of 36 × 38 × 1.6 mm³ (0.34λ_l × 0.36 λ_l × 0.016 λ_l) and has impedance bandwidth 2.86–13.3 GHz at |S₁₁| < −10 dB level. Measured band notches are achieved at 3.75/5.43/7.87/8.62/9.87 GHz centre notched frequencies to eliminate worldwide interoperability for microwave access (WiMAX) band (3.45–4.0 GHz), wireless local area network (WLAN) band (5.15–5.90 GHz), X-band for satellite communication (6.77–8.00 GHz), ITU-8 band (8.3–9.1 GHz), and radio navigation (RN) band (9.3–10.6 GHz), respectively. Variation of slot parameter on individual band notch is also investigated. Omnidirectional radiation pattern for XZ-plane and dipole-like radiation pattern for YZ-plane are observed. Stable gain, variation of phase response in linear fashion and group delay <1.3 ns for whole ultra-wideband except at band notches is achieved.     

一种新颖的宽带圆极化单极天线

该文设计了一种新颖的宽带圆极化单极子天线,该天线采用微带馈电模式。天线由C型贴片和改进的地板组成,整个天线尺寸仅为25×25×1 mm³。通过在C型贴片上切角和在地板上增加三角形微扰结构,可以有效增加天线的阻抗带宽和轴比带宽。该文给出了天线的设计流程,从表面电流分布分析了圆极化天线的工作机理。加工了天线实物,并对其进行了测量。仿真和实测结果表明天线具有超宽的阻抗带宽和轴比带宽。天线的工作频带为4.35～12 GHz(相对带宽为93.6%),3 dB轴比带宽为4.15～11.8 GHz(相对带宽为95.9%)。测量了天线的辐射性能和增益特性,实测结果与仿真结果吻合较好,证明了该天线的有效性。该天线可以应用于超宽带无线通信系统和卫星通信系统中。     

A compact dual band-notched UWB circular monopole antenna with parasitic resonators

A compact dual band-notched Ultra-wideband (UWB) circular monopole antenna that has two parasitic resonators in the ground plane is presented in this paper. The Inverted–U and Iron shaped parasitic resonators are located on the back side of the radiating patch to achieve the band rejection characteristics from 5 to 5.4 GHz for WLAN and 7.8 to 8.4 GHz for ITU band respectively. By cutting a rectangular slot on the ground plane, additional resonance is excited at the higher frequency band, and hence much wider impedance bandwidth can be attained. Applications of the proposed dual band-notched ultra-wideband (UWB) antenna structure with 5.2 GHz and 8.2 GHz center frequencies are demonstrated experimentally. Measured and simulated results of the magnitude of S₁₁, radiation patterns and realized gains show good agreement.     

具有陷波特性的改进Sierpinski分形超宽带天线

为了避免WLAN窄带通信系统对超宽带通信系统的干扰,该文提出一种具有陷波特性的改进 分形超宽带天线。天线的辐射单元是改进的 阶 分形结构,通过采用共面波导馈电技术以及增加 分形的迭代次数,可有效展宽天线的带宽,从而实现覆盖 频段的宽频特性。在分形贴片上增加两个对称的L型开路枝节,实现了 频段的双陷波特性,能有效抑制WLAN频段对超宽带通信系统的干扰。天线的尺寸较小,仿真和实测结果表明天线可广泛适用于各种UWB通信系统。     

Integrated amateur band and ultra-wide band monopole antenna with multiple band-notched

This paper presents the integrated amateur band and ultra-wide band (UWB) monopole antenna with integrated multiple band–notched characteristics. It is designed for avoiding the potential interference of frequencies 3.99 GHz (3.83 GHz–4.34 GHz), 4.86 GHz (4.48 GHz–5.63 GHz), 7.20 GHz (6.10 GHz–7.55 GHz) and 8.0 GHz (7.62 GHz–8.47 GHz) with VSWR 4.9, 11.5, 6.4 and 5.3, respectively. Equivalent parallel resonant circuits have been presented for each band-notched frequencies of the antenna. Antenna operates in amateur band 1.2 GHz (1.05 GHz–1.3 GHz) and UWB band from 3.2 GHz–13.9 GHz. Different substrates are used to verify the working of the proposed antenna. Integrated GSM band from 0.6 GHz to 1.8 GHz can also be achieved by changing the radius of the radiating patch. Antenna gain varied from 1.4 dBi to 9.8 dBi. Measured results are presented to validate the antenna performances.     

Dual band monopole antenna based on metamaterial structure with narrowband and UWB resonances with reconfigurable quality

In this article, an Ultra Wide Band (UWB) monopole antenna based on Metamaterial (MTM) unit cell with reconfigurable feature has been developed. The proposed antenna covers 3.1–10.6 GHz for UWB applications and it has a reconfigurable narrow-band for L-band (1.27 GHz) and wireless applications. The gaps in Split Rings Resonator (SRR) element are made for the Left-hand capacitance and Ω-shape strip layer by four via junctions are used for Left-hand inductance. The antenna is printed on FR-4 low cost substrate with relative permittivity of 4.4 and thickness of 1.6 mm. The total size of the antenna is 40 mm × 40 mm. The simulation is carried out using HFSS commercial full-wave software. In addition, the experimental results are presented and compared with simulated results. The antenna gives a maximum peak gain of 6 dBi with Omni-Directional radiation pattern and high efficiency of more than 70%. By embedding four switches in Ω-shape strip layer, a reconfigurable antenna has been successfully designed for wireless applications with sufficient qualification. The monopole part covers the UWB spectrum and the CRLH is responsible for the controllable narrowband resonance. The simulation and experimental results are confirmed by the numerical results.     

An antipodal Vivaldi antenna with band-notched characteristics for ultra-wideband applications

An antipodal Vivaldi antenna (AVA) with band-notched characteristics is proposed in this paper for ultra-wideband (UWB) applications. For UWB systems, there will be some interference from the narrow band systems. The proposed antenna adopts resonant parallel strip (RPS) to reject an unwanted narrow band. It is easy to tune the RPS to eliminate the interference band. To validate this approach, a printed AVA with RPS is simulated and fabricated. From 2 to 9 GHz, the proposed antenna shows a good result with approximate 2:1 VSWR, an average gain of 6.5 dB, and stable radiation patterns except the notched band. At the center frequency of the notched band, the measured results show that the VSWR is more than 8:1, the realized gain is less than −10 dB and a messy radiation pattern is achieved. The simulated and measured results are in good agreement.     

具有陷波特性的超宽带准自补天线设计

提出一种新型的微带馈电准自补天线,其辐射贴片由矩形和扇形金属片构成,并在地板上刻与辐射元互补的缝,天线整体尺寸为25 mm×32 mm×1 mm,为进一步展宽带宽,在馈电点下方的地板上挖去一个矩形缺口。仿真结果表明:驻波比小于2的带宽覆盖3.04~11.00 GHz,在整个工作频段有良好的辐射方向图。通过在馈线上嵌入U型槽,实现了对WLAN频段的陷波,而通带内仍可保持稳定的增益。     

具有三阻带特性的新型平面超宽带天线研究

设计了一款具有三阻带特性的紧凑型超宽带天线。该天线采用共面波导结构进行馈电且能覆盖3.05~11.05 GHz的频率范围。通过在地表面加载两个对称的L形槽可以滤除WiMAX和卫星通信系统对超宽带系统的干扰,同时5.15~5.25 GHz和5.725~5.825 GHz的WLAN系统对超宽带系统的干扰分别被加载在辐射贴片上的倒C形和馈线上的倒U形槽滤除。天线经过设计,优化和制作,并对其进行了测试。测试结果表明,该天线尺寸为23mm×30 mm,其在3.05~11.05 GHz内VSWR小于2,并在3.30~4.16,5.0~5.4和5.6~6.0 GHz处形成了三个阻带。     

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0.350.35,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。     

一种双阻带椭圆单极子UWB天线的设计

通过仿真与实际测试结合的方法,研究并设计了一种用于UWB通信的、具有双阻带特性的紧凑椭圆单极子天线。双阻带特性是通过在辐射单元上插入一个缝隙和在馈线上引入一共面波导谐振单元实现的。测试结果表明此天线在3.45~3.75 GHz(覆盖了WIMAX频段)和5~6 GHz(覆盖了5.15~5.85 GHz的WLAN频段)分别有两个阻带,此外,驻波系数在3.1~10.6 GHz UWB的范围内小于2。天线的辐射特性也近似于全向。天线的增益和传输函数也证实了天线能达到双阻带特性。     

一种新型的具有带阻特性的超宽带微带天线

设计制作了一种新型的具有带阻特性的超宽带微带天线。天线采用50Ω共面波导馈电结构,辐射单元采用圆形金属贴片,在圆形贴片上开一个倒U形槽,实现了天线的带阻特性。测试结果表明:在频率段2.8-12.0 GHz内(除5.00-5.95 GHz外)天线驻波比小于2,且天线具有近似全向辐射的特性;而天线在频率段5.00-5.95 GHz内形成了阻带,从而有效阻隔了WLAN(5.150-5.825 GHz)频率段。该天线具有尺寸小,易于与微波电路集成等优点,可以用于超宽带系统。     

Design of a novel sextuple band-notched UWB antenna

A novel sextuple band-notched UWB antenna was designed. Sextuple band-notched characteristics could be realized by adding a T-shaped stub, a bent stub, and etching a U-shaped slot on the patch, adding a C-shaped stub, an anti-C shaped stub near microstrip line and etching a pair of L-shaped slots on the ground plane,which effectively sup-presses the interference between narrow band systems and UWB systems. The influence of the proposed structures on band-notched characteristics was studied, and band-notched principle was explained by antenna surface current and equivalent circuit. Finally the antenna was fabricated and measured. The measured results of VSWR, radiation patterns and gains agree well with the simulated results, which demonstrates the correctness of the design method. The proposed antenna has good performance and can be widely used due to its sextuple band-notched characteristics.     

Design of band-notched antenna with DG-CEBG

Ultra-wideband (UWB) disc monopole antenna with crescent shaped slot for double band-notched features is presented. Planned antenna discards worldwide interoperability for microwave access (WiMAX) band (3.3–3.6 GHz) and wireless local area network (WLAN) band (5–6 GHz). Defected ground compact electromagnetic band gap (DG-CEBG) designs are used to accomplish band notches in WiMAX and WLAN bands. Defected ground planes are utilised to achieve compactness in electromagnetic band gap (EBG) structures. The proposed WiMAX and WLAN DG-CEBG designs show a compactness of around 46% and 50%, respectively, over mushroom EBG structures. Parametric analyses of DG-CEBG design factors are carried out to control the notched frequencies. Stepwise notch transition from upper to lower frequencies is presented with incremental inductance augmentation. The proposed antenna is made-up on low-cost FR-4 substrate of complete extents as (42 × 50 × 1.6) mm³.Fabricated sample antenna shows excellent consistency in simulated and measured outcomes.     

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。     

宽带平面直角双频单极天线

对于超宽带系统,需要具备可工作频率为3.1~10.6GHz的宽带天线。本文介绍了四种宽带平面单极天线,分别为圆形平面单极天线、平面直角单极天线、平面双频单极天线和平面直角双频单极天线。其中平面直角单极天线兼具宽频和全向特性,平面双频单极天线和平面直角双频单极天线在两个谐振点都具有宽带特性,平面直角双频单极天线在整个频带内水平面的辐射方向图几乎都可以达到全向。     

一种新型平面结构的双陷波超宽带天线设计

为了避免现存的一些窄带通信系统对超宽带天线的干扰,提出了一种具有双陷波特性的超宽带天线结构。由于采用了渐变式阶梯阻抗匹配结构作为超宽带基础天线的馈电,使天线具有了宽阻抗匹配能力。通过在基础天线背面附加双偏T寄生单元和在辐射贴片上开窗的联合方法,实现了超宽带天线的双陷波特性。天线电流分布结果可以完全反映出在陷波频率下两种方法的谐振抑制作用,而且实验结果表明该结构的天线对 WLAN(5.15～5.825 GHz) 和WiMAX(3.4～3.69 GHz)频段的信号起到了有效的抑制作用,同时在工作频段内表现出较好的全向辐射特性。     

超宽带信道建模中基于压缩感知的解卷积算法

针对频域测量方式下的超宽带(UWB)信道测量数据后处理,该文提出了用具有高斯滚降特性过渡带的类高斯窗,提取符合中国UWB频谱规范的信道测量数据,并将类高斯窗对应的时域脉冲作为先验信息,使用基于压缩感知(CS)的算法对时域信道测量信号解卷积,使得解卷积后的信道冲激响应具有高分辨率特性。利用频域加窗补零,以及改变解卷积算法中参数化波形字典原子的步长,可以得到不同分辨率的解卷积结果。采用匹配追踪(Matching Pursuit,MP)算法作为CS的重构算法。针对一间办公室的视距(LOS)与非视距(NLOS)信道测量数据处理结果表明,基于压缩感知的解卷积算法可以用较少的观测值获得和CLEAN算法相近的解卷积性能。     

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。