A novel compact his-EBG structure and its application in reduction of printed antenna mutual coupling

Anovel compact E shape High Impedance Surface (HIS) Electromagnetic Band-Gap (EBG) comprising Amended Minkowski Fractal Boundary (AMFB), Added Metal Strips (AMS), and metal plated via printed on a Rogers TMM 10i (ɛ _r =9.8, t=2.0 mm) substrate is presented. The first order AMFB and ABS are introduced for equivalent capacitance enhancement and miniaturization with effective space-filling characteristics. The dimension of lattice size is only 0.058λ ₀. The proposed structure exhibits a most compact characteristic about 35% size reduction as compared with conventional mushroom-like HIS-EBG, and better surface-wave decoupling of around 9 dB at the operating frequency band. Details of design parameters which affect the whole performance of certain band-gap are intensively investigated. A constructed prototype is potential candidate for antenna system performance enhancement.     

一种抑制同步开关噪声的新颖电磁带隙结构

电源平面与接地平面间的同步开关噪声是现代高速、高性能数字电路应用的瓶颈之一。文中提出了一种应用于印刷电路板的新颖二维电磁带隙（MS-EBG）结构,其单位晶格由折线缝隙组合与正方形贴片桥接构成,以抑制同步开关噪声。结果表明,抑制深度为-30 dB时,与传统L-bridged EBG结构比较,新EBG结构的阻带宽度增加1.3 GHz,相对带宽提高了约10%,能够有效抑制0.6～5.9 GHz的同步开关噪声。     

Development of phased array antenna by controlling the filling factor of periodic structure

A phased array antenna is realized by utilizing the variation of filling factor (FF) of electromagnetic bandgap (EBG) structures. The variation takes place under the feed line of a 4‐element array that gives the change in relative phase shift. The phase shift achieved from different combinations of EBGS lying under the feed lines is used in personal computer aided antenna design software, PCAAD 4.0, to see the beam steering capacity. Then the same feed lines are connected with four microstrip patches to yield a 4‐elements phased array antenna. The 4‐elements phased array antenna is simulated in electromagnetic (EM) software Zeland IE3D. Finally, the design is fabricated with the help of milling machine that takes the help of ISOPRO and QUICKCAM software. It can be seen that the beam steering angle increases with the increase of FFs. Thus a novel FF of EBGS based phased array antenna is developed. © 2007 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2007.     

THEORETICAL ANALYSIS OF A NOVEL PERFORMANCE-ADJUSTABLE EBG－2-D FERRITE EBG

A novel adjustable Electromagnetic Band-Gap （EBG）-2-D ferrite EBG is analyzed, whose per- formance is controllable by changing applied dc magnetic field. The finite element method of the hybrid of edge-elements and node-elements incorporated with vector Floquet＇s theorem is adopted for calculating the scattering properties of this kind of EBG. By changing the directions of the dc magnetic field and altering the strength of magnetic field, the scattering properties of the ferrite EBG are analyzed. Results show that the performance of the EBG devices is adjustable by changing the directions and strength of the dc magnetic filed, which indicates the possibility ofR/D a novel performance-adjustable EBG.     

EBG对圆波导介质棒相控阵扫描特性的改善

将电磁带隙(EBG)结构应用到圆波导介质棒相控阵列中,利用EBG结构所具有的表面波带隙特性有效消除了相控阵中的扫描盲区.比较了无限阵列的扫描特性和有限阵列中心单元方向图在EBG加载前后的变化.仿真分析表明,以EBG结构作为圆波导介质棒相控阵的地平面,能有效消除扫描盲区,扩展扫描范围.     

应用EBG结构抑制电磁干扰的研究

电磁带隙结构(EBG)是一种周期性结构,具有明显的带阻特性。首先介绍了EBG结构的特点,通过理论分析计算和仿真,阐述了其禁带形成的原因,依据EBG结构所具有性质的特点,分析了该结构对表面电流的影响。并利用EBG结构带阻特性以及影响表面电流的特性,将其应用于抑制表面电流从而减小电磁干扰(EMI)。通过仿真建模实验、数据测量得到的结果,说明了将EBG结构应用于抑制电磁干扰的可行性。     

二维电磁带隙结构研究的新方法

应用悬置微带线方法(SMM)对二维EBG结构进行了测量和计算。对二维电小EBG(UC—EBG和PV—EBG)的特性用SMM法进行了统一的实验和仿真分析。与其他方法对比，由于采用了“强耦合”结构，更能显现出二维电磁带隙结构的特性。同时提出了新型的悬置微带贴片的EBG天线，该天线结构紧凑，更利于EBG的实际应用。     

一种抑制同步开关噪声的超宽带电磁带隙结构

针对谐振电磁带隙（Electromagnetic Band Gap, EBG）结构带宽比较窄的问题,通过研究EBG的等效电路模型,提出了一种新颖的垂直级联型EBG结构.同时使用Ansoft HFSS软件对所设计的结构进行仿真分析及验证.仿真结果表明：新结构在抑制深度为-40 dB时,阻带范围为0.75～15.7 GHz,具有14.95 GHz噪声抑制的超带宽特性.与同尺寸的传统单过孔Mushroom EBG结构相比,带宽增加3.65 GHz,相对带宽提高32.3 %.新结构为改善EBG结构抑制噪声带宽提供一种理论参考的新方法.     

一种扩展蘑菇型EBG结构阻带带宽的新方法

该文根据蘑菇型电磁带隙(EBG)结构的等效电路原理提出一种插入交指电容的方法,实现扩宽蘑菇型EBG结构阻带宽度,并设计一种T型交指电容EBG结构验证该方法的有效性。-30 dB时该结构相对于蘑菇型EBG结构,阻带下截止频率从0.9 GHz降到290 MHz,带宽从6.1 GHz提高到7.1 GHz。在不改变EBG结构单元面积,并增加交指单元层数和降低单元厚度的情况下,通过仿真验证该方法可有效提高抑制同步开关噪声的能力。     

Compact wideband microstrip thinned array antenna using EBG superstrate

A compact wideband microstrip array antenna with EBG superstrate is presented. We compare and summarize the results for the impedance bandwidth and gain characteristics of three different antenna prototypes, namely two conventional 2 × 2 arrays with EBG superstrate and 2 × 2 array of multiple resonator patches with EBG superstrate. The designed antenna has a moderate gain of over 8.5 dBi and a wideband impedance bandwidth of over 20%, which covers the required bandwidth of the WLAN (2.4-2.484 GHz) and WiMAX (2.3-2.5 GHz) systems. The EBG superstrate is also utilized to achieve a thin antenna with a cavity height of λ₀/16 at the center frequency of 2.45 GHz. The proposed antenna is low-cost and low-profile, having overall dimension of 0.9 λ₀ × 0.9 λ₀ × 0.081 λ₀ (110 mm × 110 mm × 9.9 mm).