一种基于人工电磁超材料的宽带MIMO天线去耦方法

本文提出了一种新的基于人工电磁超材料的宽带MIMO(Multiple-Input Multiple-Output)天线的去耦方法,通过在两个天线单元之间周期性放置开口三角环形谐振器（open triangular ring resonators,OTRRs）来降低耦合度。多个不同谐振频率的OTRRs有效地增强了去耦带宽,与未加载去耦结构的MIMO天线相比,在5.2GHz频段,百分比带宽为5.74%,隔离度提高了9dB以上。     

Mutual Coupling Reduction of MIMO Antenna Array Using Meta-FCRR

In order to reduce mutual coupling interference of between both adjacent antenna elements, a practical scheme for metamaterial is reported in this paper. The study shows that the permittivity and permeability of metamaterial based on fold complementary ring resonator (FCRR) can well be anastomosed in electromagnetic field. The antenna array using co-planar waveguide mode to expound the multiple input multiple output (MIMO) performance are further proposed. The results of simulated antenna array with FCRR indicate that the coupling of about 30.5 dB, 14 dB and 20.2 dB are reduced at resonance frequency (at 2.4 GHz, 6.15 GHz and 9.2 GHz). Meanwhile the experimental measure results can meet the simulation data. Additionally, the envelope correlation coefficient (ECC), diversity gain (DG), voltage standing wave ratio (VSWR) are better characteristics in contrasting to without FCRR, making the solution viable for MIMO antenna arrays.

     

偏振不敏感的九聚物太赫兹超材料

在实验上提出将九个开口谐振环以第一个谐振环的开口方向为基准按照涡旋状的轨迹排布,且依次将开口环逆时针扭转40,构成九聚物太赫兹超材料,并在理论上系统研究了该超材料的传输特性。将原本只具有单一谐振模式的开口谐振环按照类似于低聚物的结构排布方式构成周期单元结构时,利用结构末端引起的能量耦合来增强相邻谐振器间的能量耦合,便会有更多的谐振模式产生,最终实现偏振不敏感的效果。这种思路丰富了传统超材料离散结构的设计理念,为太赫兹超材料功能器件,如开关,调制器和滤波器等的设计提供了一种新的参考方案。     

A Triangular Complementary Split Ring Resonator Based Compact Metamaterial Antenna for Multiband Operation

Wireless Personal Communications - In this paper, a triangular complementary split ring resonator (TCSRR) based compact metamaterial antenna for multiband operation is presented. TCSRR is used to...     

太赫兹多波段的电磁诱导透明设计与分析

设计了一种超材料三维模型,由闭合方环和4个开口谐振方环通过正、反向双开口方环与闭合方环相互耦合来组成,在太赫兹范围内具有多波段电磁诱导透明(EIT)效应。该结构分别实现了在1.21、1.46、1.61、1.98 THz这四波段的电磁诱导透明现象,并且谐振强度均达到0.9左右。通过将结构单元进行拆分并相互对比分析,研究了该超材料结构产生多波段EIT效应的物理机理,并重点分析了开口大小、闭合方环尺寸对EIT强度与带宽的影响。通过对三维立体结构仿真分析可知,所设计的超材料不仅在多个波段获得了较高的折射率灵敏度,还具有高强度、多频点的慢光效应。因此,其在折射率传感与光缓存器件等领域,具有良好的应用前景。     

Metamaterial inspired quad band circularly polarized antenna for WLAN/ISM/Bluetooth/WiMAX and satellite communication applications

A CPW fed metamaterial inspired Quadband circularly polarized antenna is presented in this article. The proposed antenna consists of defected ground structure with a radiating stub, which is at opposite side of the feedline. A waveguide mode of analysis is carried out for split ring resonator (SRR) and complimentary split ring resonator (CSRR) to enhance the properties of metamaterials. The proposed antenna analysis is taken iteration wise and used FR-4 Material as the substrate material with Ɛ_r = 4.4 and analysed using ANSYS electromagnetic desktop. The designed antenna projecting the peak gain of 4.8 dB and it is working in the application bands of WLAN/ISM/Bluetooth at 2.4 GHz, 5.8 GHz and 3.35 WiMAX band, X-band downlink satellite communication system (7.25–7.75 GHz) and ITU band (8–8.5 GHz) with fractional bandwidth of about 70%. Proposed antenna exhibits circular polarization at 2.39–2.55 GHz, 3.05–3.1 GHz, 4–5 GHz and 6.3–6.64 GHz respectively. To know the signal integrity of the antenna, time domain analysis is carried out for identical antennas in two conditions (face to face and side by side) with the help of CST microwave studio. The designed antenna showing excellent correlation in measurements with respect to simulation results.     

Microstrip Sierpinski fractal carpet for slot antenna with metamaterial loads for dual-band wireless application

The compact microstrip antennas with the dual-band characteristic and reconfigurable qualification have been noticed and investigated in this paper. We have developed the slot microstrip antenna with Sierpinski carpet and Minkowski formations and then the metamaterial loads are placed on this antenna in the slot area. The reflection/transmission method has considered to obtain the permittivity and permeability of the split ring resonator (SRR) as a metamaterial. Finally, we show that by using some junction in the metamaterial layer, we can obtain reconfigurable characteristic. Both antennas have dual-band characteristic where the first antenna has two resonances at 3.2 and 4.5 GHz and in the second antenna by altering the metamaterial layer both resonances are occurring at 3.5 and 5.8 GHz. We show that the antenna has two resonance frequencies that matched with the metamaterial Double Negative (DNG) characteristic. Both antennas are printed on FR-4 also we compared measurement and simulation results together. Aforementioned antennas cover the main wireless, WiMAX and LTE bands with sufficient gain and high efficiency (more than 80% typically) with a bi-directional radiation pattern for the indoor application. Here, the metamaterial is used for controlling the resonances and Sierpinski carpet is developed for matching.     

Conformal Band Notched Circular Monopole Antenna Loaded with Split Ring Resonator

This article presents the design and analysis of conformal circular monopole antenna with split ring resonator to get frequency notch characteristics in the wideband. Split ring resonators placed on one side of the substrate and complementary split ring resonators placed on the other side of the substrate at defected ground structure, which yields the frequency notch characteristics with respect to the microstrip feeding. Dual notch band characteristics are obtained between 4–4.3 and 7.3–8.1 GHz. The analyzed conformal characteristic of the antenna supports excellent constant reflection coefficient characteristics over the band at different angles. The impedance and radiation characteristics of the antenna model is analysed in simulation along with unit cell analysis of the SRR and the measured results are providing good agreement with them.     

High Gain Compact Multiband Cavity-Backed SIW and Metamaterial Unit Cells with CPW Feed Antenna for S,and Ku Band Applications

A compact multiband cavity-backed substrate integrated waveguide (SIW) and metamaterial antenna with coplanar waveguide (CPW) feed is designed for S and K_u bands thereby providing low and high frequency applications. Designing simultaneous achievement of high gain in S band and K_u band antennas are challenging task, but the proposed antenna overcomes this limitation. The proposed antenna has a ground structure with radiating T-shaped stub opposite to the feed line and a combination of SIW and metamaterial. SIW and complementary square split ring resonator (CSSRR) are used to enhance efficiency, directivity, gain and bandwidth. The proposed antenna structure uses FR-4 epoxy as the substrate material with ?_r?=?4.4 with a dimension of 40 × 40?×?1.6 mm and analyzed using ANSYS HFSS. The designed antenna resonates at three frequencies (i.e.), 4.23, 13.63 and 17.05 GHz with a gain greater than 5 dBi and efficiency greater than 80%. It is suitable for S band (ISM, WLAN, WiMax) and K_u band (radar, satellite communications) applications. The designed antenna is linearly polarized with high gain and efficiency at both the bands.

     

Dual band microstrip patch antenna array loaded with split ring resonators and via holes

Reduction in antenna size by using multi-band radiators play a vital role in the miniaturization of present world wireless handheld devices, as dual band behaviour of the antennas result in the integration of more than one communication standard in a single system and thus, saving the installation space required for separate antennas. In this context, this communication presents a shorted-pin dual band metamaterial inspired microstrip patch antenna array. Under the unloaded conditions, the traditional patch antenna array resonates at 5.8 GHz with gain of 9.8 dBi and bandwidth of 540 MHz. However, when each patch of this traditional antenna array is loaded with split ring resonator (SRR) and a metallic via hole is introduced in the patch, the same antenna array produces an additional resonant frequency in IEEE 802.11b/g/n 2.45 GHz Wi-Fi band with bandwidth and gain of 290 MHz and 5.6 dBi, respectively, while the initial resonant frequency (i.e. 5.8 GHz) gets shifted to IEEE 802.11ac 5 GHz Wi-Fi band, providing the gain and bandwidth of 11.4 dBi and 510 MHz, respectively. The proposed antenna array has been fabricated, and the measured results are presented to validate the proposed array. Moreover, the equivalent circuit of the proposed antenna array has been designed and analyzed to validate the simulated, measured and theoretical results. Attainment of dual band characteristics by incorporating the metamaterial with single band traditional patch antenna array makes this structure novel, as this has been achieved without any extra hardware cost, size and loss of structural planarity. Also, both the frequency bands of this proposed metamaterial inspired antenna array possess considerable gain and bandwidth.     

超宽频单极子陶瓷介质谐振器天线设计与仿真

设计了一种尺寸小、频带宽、结构简单的单板子陶瓷介质谐振器天线,该天线经由在单板子周围加一个环形的介质谐振器而成.该设计主要通过在环形谐振器中使用高介电常数的陶瓷材料降低天线的尺寸,利用环形谐振器与单板子谐振频率之间的耦合展宽天线的频带.利用仿真软件HFSS为该天线建立模型并进行优化仿真,得到了最佳的天线设计参数,优化所...     

Mutual Coupling Reduction in Microstrip Patch Antenna Arrays Using Simple Microstrip Resonator

Wireless Personal Communications - In this paper a novel ladder resonator is introduced to reduce mutual coupling effect in the patch antenna array structure. Applied patch antennas are operating...     

A Rectangular SRR Switched Slotted Microstrip Patch for Frequency Diversity Application

Planar antenna with a specific resonant mode is essential to meet the diversity demand for wireless communication. This paper presents modeling and experimental validation of a microstrip antenna design in which multiple resonant frequencies are excited based on different negative permeability response of the rectangular split ring resonator (SRR). The antenna geometry consists of a slotted patch with split ring resonator loaded between its two arms. The patch was fabricated on FR-substrate of relative permittivity ε_r?=?4.4, and has a size of 30.5 mm?×?34 mm. In the antenna desing, PIN diodes connect the outer ring and inner ring resonator of the SRR to the adjacent arms of the patch. Under various bias conditions, quad-band resonance was observed at 2.07 GHz, 2.11 GHz, 2.31 GHz, and 2.46 GHz. The measured S₁₁ results are found comparable to the simulated data, and demonstrate proper functioning of the proposed antenna with stable gain and radiation patterns.     

超宽带单极子加载介质谐振器天线的设计

该文设计了一种尺寸小,频带宽,结构简单的单极子陶瓷介质谐振器天线。在单极子天线周围加载一个环形的陶瓷介质谐振器,利用环形谐振器与单极子谐振频率之间耦合来展宽频带。利用仿真软件HFSS建立天线的模型,并对模型进行优化仿真,得到了最佳的天线设计参数,仿真得到的天线频带宽度为0.7～4.6GHz,相对带宽达到了153%,使用矢量网络分析仪对该天线进行测量,实测结果与仿真值基本吻合。     

基于传输线理论的SRR结构异向介质的研究

根据裂缝环状谐振器(SRR)的结构特点,以及SRR结构在入射电磁场的作用下的电荷、电流分布关系,得到一种描述SRR的等效电路模型,应用传输线理论推导出相应的电报方程,该模型能够精确表征SRR结构复杂的本构关系.仿真数据表明,该模型所描述磁导率的变化趋势与传统的分析方法的结果相吻合;预测SRR的谐振频率精度高.验证了该等效电路模型是合理的、可信的,对分析其负磁导率的产生机理、设计性能更完善的SRR结构的异向介质具有指导意义.     

基于零折射超材料的双频高增益微带天线*

基于双面对称单环开口谐振器对结构奇异的电磁特性,设计了一种频率可控的各向异性零折射超材料。将这种零折射超材料应用于普通双频微带天线,制备了中心频率为5. 15GHz 和6. 8GHz 的零折射双频微带天线。仿真和测试结果显示,由于零折射超材料的引入,天线的侧向辐射减弱,方向性增强。在低频工作时,零折射微带天线E 面和H 面半功率波束宽度分别减小了29°和10°,增益提高了2. 2 dB。在高频工作时,零折射微带天线E面和H 面半功率波束宽度均减小了16毅,增益提高了2. 4 dB。将零折射超材料应用于微带天线的介质基板,为高性能双频微带天线设计提供了有效途径。     

A novel design of circularly polarised antenna based on metamaterial

This article presents a novel design of circularly polarised microstrip antenna based on a metamaterial reflection plane and a half-wave antenna. The metamaterial is composed of two pieces of substrates coated on one side with split ring resonators. Both the experimental and simulated results show that good circularly polarised radiation performances are obtained. The 10?dB return-loss impedance bandwidth and 3?dB axial ratio bandwidth of proposed antenna are 12% and 7%, respectively, and the gain of proposed antenna compared with the half-wave antenna is improved from 6?dB to 9?dB in the design frequency range.     

非对称共面波导复合左右手传输线的多频天线

设计了一种新型的基于非对称共面波导(ACPW)馈电复合左右手传输线(CLRH-TL)的四频段混合小型化天线。天线由非对称共面波导接地面加载互补开口谐振环缝隙、单极子天线终端加载复合左右手传输线单元组成,将常规单极子天线与超材料结构的零阶谐振器天线双模式混合。实测结果表明：天线回波损耗大于10 dB的阻抗带宽分别为1.55~1.65 GHz,2.4~3.7 GHz,5.15~5.36 GHz,5.71~5.89 GHz,通带内具有良好的辐射特性。天线结构简单紧凑,易于集成,可应用于GPS,WLAN和WiMAX无线通信系统中。     

Pulse Delay and Advancement in SOI Microring Resonators With Mutual Mode Coupling

In this paper, we experimentally demonstrate continuously tunable pulse propagation in SOI microring resonators with mutual mode coupling, which is induced by nanosized gratings along the ring sidewalls. In the presence of the mutual mode coupling, dispersion-induced group delay is investigated in single-waveguide and double-waveguide coupled single-ring resonators, respectively. In particular, pulse propagation in the drop channel of a double-waveguide coupled resonator is observed and exhibits continuously tunable delay and advancement features in the experiment. Delayed pulses are also obtained at the reflection port of a single-waveguide coupled resonator due to the existence of backward whispering gallery mode (WGM).     

基于谐振环的太赫兹吸波体等效电路研究

以常规开口环谐振器(Split ring resonator,SRR)结构的"超材料"太赫兹吸波体为例,首先用CST Microwave Studio软件对吸波体的吸波特性进行仿真。然后,根据横电(TE)模和横磁(TM)模入射时表面电流分布情况,分别建立了超材料太赫兹吸波体对两种入射模式的等效电路模型。最后,从理论上对等效电路模型进行了验证,并利用等效电路模型研究了吸波体结构参数对其吸收峰位置的影响规律。提出的等效电路模型对于"超材料"太赫兹吸波体的结构设计与性能分析具有十分重要的指导和参考价值。