陷波可重构的超宽带缝隙天线设计

本文提出一种陷波可重构的超宽带缝隙天线.采用六边形缝隙和带有矩形辐射枝节的渐变微带馈线实现超宽带.通过在馈线旁加载倒L型寄生单元及在矩形枝节刻蚀倒U型缝隙,天线分别实现WiMAX和WLAN频段的陷波.在寄生单元和倒U型缝隙上加载开关元件,控制开关的不同组合状态实现陷波可重构.天线的尺寸为24.5mm×20.5mm(0.40λg×0.33λg,λg为低频导波波长).仿真和测量结果表明:天线可以工作在超宽带、两个单频带陷波、一个双频带陷波4种工作模式.     

一种新型的双陷波UWB天线研究与设计

为了有效地抑制窄带信号对超宽带系统的干扰,设计了一种新型双陷波平面超宽带天线,地板采用新型的缺陷地结构来扩展带宽,并通过在八边形天线的辐射贴片上加载互补开口谐振环、在馈线上开U形缝隙,使得天线在3.7～4.1 GHz和5.1～5.9 GHz频段内实现双陷波特性.分析了实现天线陷波的原理,研究了天线的尺寸参数对陷波的影响,并对所设计的天线进行了实物加工和测试.结果显示,该天线能够有效地抑制卫星C波段和无线局域网系统的干扰,远场方向图和增益特性良好,在整个超宽带系统工作带宽内具有较好性能,是一种能广泛应用于超宽带系统的新型超宽带天线.     

陷波可重构的超宽带单极天线设计

本文提出了一个陷波可重构的超宽带单极天线.为了实现超宽带,辐射单元采用阶梯式结构.在辐射单元刻蚀一个开口缝隙,并在缝隙的适当位置放置三个开关,通过控制开关的不同组合状态实现陷波可重构.天线的尺寸为30mm×22mm(0.42λg×0.31λg,λg为低频导波波长).仿真和测量结果表明:天线可以工作在超宽带以及3个陷波可重构频段,超宽带工作频带为3.1GHz~10.7GHz,陷波频段涵盖3.4GHz~3.69GHz,3.7GHz~4.2GHz和5.2GHz~5.875GHz.     

一种具有5.8GHz WLAN深度抑制特性的超宽带全向天线

为超宽带室内定位系统设计了一种具有5.8 GHz WLAN深度抑制特性的超宽带单陷波全向天线.采用“倒箭头”形贴片作为辐射单元,在矩形地面上刻蚀矩形开路槽和直角三角形截断,获得了宽的阻抗带宽;在辐射贴片上刻蚀1个半波长C形槽,并在地面上刻蚀1个半波长RSCSRR槽对,实现了5.8 GHz WLAN信号的深度抑制.仿真结果表明,天线的阻抗带宽为3.10 GHz～10.60 GHz, 5.8 GHz陷波处的电压驻波比达7.59.实测的S₁₁曲线与驻波比曲线与仿真结果吻合良好,验证了陷波的有效性;4 GHz, 6.5 GHz, 9 GHz频点的实测方向图表明天线在整个超宽带频段内具有良好的辐射特性和全向性,满足超宽带室内定位系统天线的设计需求.     

新型古币形超宽带分形印刷天线的设计

共面波导和分形结构结合应用,在展宽天线带宽方面具有独特优势.提出了一种新型古币形超宽带分形天线,采用共面波导馈电,并加载分形缝隙,天线的阻抗带宽大幅提高.给出了天线的表面电流、回波损耗、方向图和增益结果.对3阶分形天线进行了加工与测试,测试结果表明,天线带宽达到2.6～16 GHz,带宽比大于6:1.仿真结果与测试结果基本吻合,为超宽带小型化天线的设计提供了新的思路．     

一种双面超宽带双陷波天线

近年来,随着超宽带通信技术的不断成熟,超宽带天线的应用愈加广泛.为了有效的滤除WiMAX和X波段信号对超宽带天线产生的电磁干扰,研制了一种基于CSRR结构的新型双面超宽带双陷波天线.新型天线的主体结构是材质为FR微波介质的基板,通过蚀刻双面覆铜的FR微波介质的方法进行制作.与传统天线相比,该天线结构紧凑,尺寸较小,不仅...     

基于超表面的紧耦合阵列天线设计

设计了一种应用于WiMAX的紧耦合阵列天线。基于超表面解耦原理,设计了一种具有负介电常数和正磁导率的耶路撒冷十字超表面单元。在二单元紧耦合贴片天线上方加载5×6的超表面以减小单元间互耦,矩形贴片上刻蚀一个U形缝隙改善天线的阻抗匹配。阵列天线的尺寸仅为55 mm×74 mm×8.2 mm(0.64λ₀×0.86λ₀×0.10λ₀,λ₀为3.5 GHz时自由空间的波长),天线单元的间距(边到边的距离)为1.3 mm(0.015λ₀)。测量结果表明,阵列天线能够工作在WiMAX的3.5 GHz频段,-10 dB阻抗带宽为13.83%(3.23 GHz～3.71 GHz),-18 dB解耦带宽为10.34%(3.3 GHz～3.66 GHz),天线具有良好的辐射特性。     

应用于5G的高隔离双频MIMO天线设计

本文设计了一种适用于5G的n41(2.496 GHz～2.690 GHz), n78(3.300 GHz～3.800 GHz)频段的高隔离双频多输入多输出天线。通过在单极子天线单元上延伸出L型枝节产生新的谐振来实现双频,并将两个结构相同的双频天线单元以对称方式进行放置。通过在两个天线单元之间的接地板上刻蚀一个C型槽来提高天线两端口之间的隔离度,在接地板上加载一个接地枝节进一步改善天线在较高工作频段的隔离度。天线实测结果表明,工作频段分别为2.55 GHz～2.75 GHz(7.5%)和3.28 GHz～3.85 GHz(16.0%),端口之间的隔离度在工作频段内分别大于22 dB, 20 dB。     

应用于认知无线电的频率可重构天线

本文提出一种应用于认知无线电的频率可重构单极子天线.阶梯型辐射单元刻蚀有一个开路缝隙,接地板刻蚀有一个短路方环形缝隙.在开路缝隙和短路缝隙上加载6个开关元件,通过控制开关的不同组合状态可以实现超宽带、单频带、双频带3种模式,从而实现频率可重构.仿真和测量结果表明天线可以工作在UWB以及WiMAX频段.     

基于交叉缝隙的陷波可重构超宽带天线

本文设计了一种基于交叉缝隙的陷波可重构超宽带天线.通过采用3×3圆形超表面,有效拓展了天线的工作带宽.通过在矩形接地面上刻蚀两组交叉缝隙,并控制缝隙中设置的二极管的通断实现了天线的陷波可重构.所设计的天线尺寸较小,控制方式简单.结果表明,所设计的天线可以工作在超宽带和陷波模式下,超宽带模式的-10 dB带宽为3.5 G...     

Metamaterial-Based Compact Antenna with Defected Ground Structure for 5G and Beyond

In this paper, a unit cell of a single-negative metamaterial structure loaded with a meander line and defected ground structure (DGS) is investigated as the principle radiating element of an antenna. The unit cell antenna causes even or odd mode resonances similar to the unit cell structure depending on the orientation of the microstrip feed used to excite the unit cell. However, the orientation which gives low-frequency resonance is considered here. The unit cell antenna is then loaded with a meander line which is parallel to the split bearing side and connects the other two sides orthogonal to the split bearing side. This modified structure excites another mode of resonance at high frequency when a meander line defect is loaded on the metallic ground plane. Specific parameters of the meander line structure, the DGS shape, and the unit cell are optimized to place these two resonances at different frequencies with proper frequency intervals to enhance the bandwidth. Finally, the feed is placed in an offset position for better impedance matching without affecting the bandwidth The compact dimension of the antenna is 0.25 λL × 0.23 λL × 0.02 λL, where λL is the free space wavelength with respect to the center frequency of the impedance bandwidth. The proposed antenna is fabricated and measured. Experimental results reveal that the modified design gives monopole like radiation patterns which achieves a fractional operating bandwidth of 26.6%, from 3.26 to 4.26 GHz for |S11|<−10 dB and a pick gain of 1.26 dBi is realized. In addition, the simulated and measured cross-polarization levels are both less than −15 dB in the horizontal plane.     

Super Compact UWB Monopole Antenna for Small IoT Devices

This article introduces a novel, ultrawideband (UWB) planar monopole antenna printed on Roger RT/5880 substrate in a compact size for small Internet of Things (IoT) applications. The total electrical dimensions of the proposed compact UWB antenna are 0.19 λ_o × 0.215 λ_o × 0.0196 λ_o with the overall physical sizes of 15 mm × 17 mm × 1.548 mm at the lower resonance frequency of 3.8 GHz. The planar monopole antenna is fed through the linearly tapered microstrip line on a partially structured ground plane to achieve optimum impedance matching for UWB operation. The proposed compact UWB antenna has an operation bandwidth of 9.53 GHz from 3.026 GHz up to 12.556 GHz at −10 dB return loss with a fractional bandwidth (FBW) of about 122%. The numerically computed and experimentally measured results agree well in between. A detailed time-domain analysis is additionally accomplished to verify the radiation efficiency of the proposed antenna design for the ultra-wideband signal propagation. The fabricated prototype of a compact UWB antenna exhibits an omnidirectional radiation pattern with the low peak measured gain required of 2.55 dBi at 10 GHz and promising radiation efficiency of 90%. The proposed compact planar antenna has technical potential to be utilized in UWB and IoT applications.     

Inkjet Printed Metamaterial Loaded Antenna for WLAN/WiMAX Applications

In this paper, the design and performance analysis of an Inkjet-printed metamaterial loaded monopole antenna is presented for wireless local area network (WLAN) and worldwide interoperability for microwave access (WiMAX) applications. The proposed metamaterial structure consists of two layers, one is rectangular tuning fork-shaped antenna, and another layer is an inkjet-printed metamaterial superstate. The metamaterial layer is designed using four split-ring resonators (SRR) with an H-shaped inner structure to achieve negative-index metamaterial properties. The metamaterial structure is fabricated on low-cost photo paper substrate material using a conductive ink-based inkjet printing technique, which achieved dual negative refractive index bands of 2.25–4.25 GHz and 4.3–4.6 GHz. The antenna is designed using a rectangular tuning fork structure to operate at WLAN and WiMAX bands. The antenna is printed on 30 × 39 × 1.27 mm3 Rogers RO3010 substrate, which shows wide impedance bandwidth of 0.75 GHz (2.2 to 2.95 GHz) with 2 dB realized gain at 2.4 GHz. After integrating metamaterial structure, the impedance bandwidth becomes 1.25 GHz (2.33 to 3.58 GHz) with 2.6 dB realized gain at 2.4 GHz. The antenna bandwidth and gain have been increased using developed quad SRR based metasurface by 500 MHz and 0.6 dBi respectively. Moreover, the proposed quad SRR loaded antenna can be used for 2.4 GHz WLAN bands and 2.5 GHz WiMAX applications. The contribution of this work is to develop a cost-effective inject printed metamaterial to enhance the impedance bandwidth and realized the gain of a WLAN/WiMAX antenna.     

Wideband microstrip antennas with sandwich substrate

A broadband microstrip antenna with low?high?low (sandwich) dielectric constant substrate combination using a microstrip line-via feed is presented for ultra-wideband applications. The proposed antenna consists of three dielectric substrates; low dielectric constant substrates that contain the microstrip feed line as well as parasitic patches and a high dielectric constant substrate that contains the driven patch. To achieve a large impedance bandwidth, parasitic patches and microstrip line-via combination feed to the driven patch in the multilayered microstrip antenna are used. The proposed antenna designed, fabricated and measured on the sandwich substrate. The antenna has measured 10 dB return loss bandwidth of 46.9% and directive gain .5.2 dBi at boresight across the impedance bandwidth. The total height of antenna is 5.77 mm or 0.077λ ^{at 4 GHz.}     

多应用环境下超高频RFID标签天线设计

 金属等环境介质对射频信号的干扰影响着无源UHF RFID系统性能在应用中的充分发挥.利用三维结构的微带天线模型将贴片天线在电气上与金属表面分离以构成与底面无关的RFID标签,但因此而加大了RFID标签结构的复杂性,造成RFID标签生产成本的增加.通过改变微带天线的馈电形式,将传统非平衡单馈电结构的微带天线改进成平衡双馈电结构,三维的微带天线也简化成平板结构,减小了RFID标签体积.该天线模型不但可以降低RFID标签制造工艺难度,也为RFID标签在不同应用环境中提供了兼容性.     

Design of a Compact Monopole Antenna for UWB Applications

In this paper, a low cost, highly efficient and low profile monopole antenna for ultra-wideband (UWB) applications is presented. A new inverted triangular-shape structure possessing meander lines is designed to achieve a wideband response and high efficiency. To design the proposed structure, three steps are utilized to achieve an UWB response. The bandwidth of the proposed antenna is improved with changing meander lines parameters, miniaturization of the ground width and optimization of the feeding line. The measured and simulated frequency band ranges from 3.2 to 12 GHz, while the radiation patterns are measured at 4, 5.3, 6 and 8 GHz frequency bands. The overall volume of the proposed antenna is 26 × 25 × 1.6 mm3 ; whereas the FR4 material is used as a substrate with a relative permittivity and loss tangent of 4.3 and 0.025, correspondingly. The peak gain of 4 dB is achieved with a radiation efficiency of 80 to 98% for the entire wideband. Design modelling of proposed antenna is performed in ANSYS HFSS 13 software. A decent consistency between the simulated and measured results is accomplished which shows that the proposed antenna is a potential candidate for the UWB applications.     

Compact multiband planar monopole antennas for smart phone applications

A compact multiband planar monopole antenna is discussed. Tuning techniques, including offset feed, etching meandered slot and cutting tuning inset, are applied to the radiator in order to maximise the operating frequency range of the antenna. Experimental results demonstrate that the proposed design covers the operating bands of seven wireless services including the DCS/PCS/W-CDMA/2.4-/5-GHz WLANs/Bluetooth and the WiMAX in United States. The design concept, step-by-step guidelines, radiation mechanism and the simulated and experimental results are carefully investigated. The finite-size ground plane effect is taken into account as well. This antenna features multiband operations, almost omnidirectional radiation patterns in one of the principal cuts, and a compact size of 22.75 times 20 mm². It is especially suitable for smart phone applications which are involving in integrating multiple wireless services into a single hand-held unit.     

Realisable rational function approximations for the equivalent circuit modelling of broadband antennas

The vector fitting (VF) algorithm is applied to the equivalent circuit modelling of an antenna over a broad frequency band. To ensure that the resulting circuit model is realisable, the passivity constraint must be imposed during the modelling process. Three methods are investigated to ensure the passivity, each based on VF: (i) the use of quadratic programming proposed earlier by Gustavsen and Semlyen, (ii) a technique based on constraining a second-order rational function and (iii) a search method using a particle swarm optimisation with constraints. These techniques are evaluated through three sample antennas: a commercial broadband horn, an ultra-wideband planar monopole with a notch-band and an active integrated microstrip antenna. The results are compared in terms of the modelling error against the model order and the computation time required.     

A Compact Rhombus Shaped Antenna with Extended Stubs for Ultra-Wideband Applications

Ultra-wideband (UWB) is highly preferred for short distance communication. As a result of this significance, this project targets the design of a compact UWB antennas. This paper describes a printed UWB rhombus-shaped antenna with a partial ground plane. To achieve wideband response, two stubs and a notch are incorporated at both sides of the rhombus design and ground plane respectively. To excite the antenna, a simple microstrip feed line is employed. The suggested antenna is built on a 1.6 mm thick FR4 substrate. The proposed design is very compact with overall electrical size of 0.18λ × 0.25λ (14 × 18 mm²). The rhombus shaped antenna covers frequency ranging from 3.5 to 11 GHz with 7.5 GHz impedance bandwidth. The proposed design simulated and measured bandwidths are 83.33% and 80%, respectively. Radiation pattern in terms of E-field and H-field are discussed at 4, 5.5 and 10 GHz respectively. The proposed design has 65% radiation efficiency and 1.5 dBi peak gain. The proposed design is simulated in CST (Computer Simulation Technology) simulator and the simulated design is fabricated for the measured results. The simulated and measured findings are in close resemblance. The obtained results confirm the application of the proposed design for the ultra-wide band applications.     

小型化超宽带微带天线的设计

本文提出了一种结构简单的小型化超宽带微带天线,尺寸为28mm×30mm．天线采用渐变馈线对酒杯状贴片馈电,接地板采用缺陷地的结构．天线参数采用电磁仿真软件CST进行仿真和优化．测量结果显示该天线在S11小于-10dB时,相对带宽是170．1％（2．4GHz～30GHz）．实际制作了天线的样品并进行了测试,实测与仿真吻合良好．