超宽带抑制同步开关噪声的新型电磁带隙结构

为抑制现代高速电路中的同步开关噪声,给出了一种新型电磁带隙结构,可超宽带抑制同步开关噪声。利用软件对新型电磁带隙结构的阻带特性及信号完整性进行仿真分析。结果表明,与相同参数的Z型桥电磁带隙结构相比,当抑制深度为-30dB时,新型电磁带隙结构的同步开关噪声抑制带宽为130MHz～10．45GHz,相对带宽增加了58．8％,阻带下限截止频率降低了130MHz;同时使用差分线对传输信号时,新型电磁带隙结构电源平面较好地保持了信号的完整性。     

一种具有新颖电磁带隙结构的印刷电路板电源平面

针对印刷电路板电源平面或地平面同步开关噪声的抑制问题,提出了一种新颖的二维电磁带隙结构.这一新颖设计基于用折线增加贴片的有效电感,单位晶格由折线、缝隙和正方形金属贴片桥接构建.结果表明,与相同参数的L形桥接电磁带隙结构比较,抑制深度为-30 dB时,新型二维电磁带隙结构的阻带宽度覆盖0.40 GHz到5.1 GHz的频率范围,相对带宽提高了约16.2%,阻带下限截止频率下降了200MHz,且具有全向抑制同步开关噪声以及采用标准印刷电路板工艺制作的优势.     

高增益电磁带隙结构微带天线设计

电磁带隙结构禁带区的电磁特性使其在微波工程得到广泛应用,在微带天线设计中常常用来提高天线的增益.对加载电磁带隙结构的微带天线进行了仿真,首先讨论电磁带隙结构与微带天线之间的间距对其辐射特性的影响:一是影响其辐射频率,二是影响其天线增益;其次,讨论不同布局的电磁带隙结构对天线增益的影响:不仅围合式结构可以增加天线的增益,...     

一种抑制同步开关噪声的微波光子晶体结构

为了确保抑制高速电路中同步开关噪声(SSN)的微波光子晶体(EBG)结构在兼顾带隙特性的同时,还具有良好的信号完整性,采用枝条绕转单元贴片的方法设计出一种新型EBG结构。利用HFSS软件对新型EBG结构抑制SSN的特性进行建模仿真,并制备刻蚀有新型EBG结构的4层印制电路板,用安捷伦矢量网络分析仪对其禁带特性进行测试,实验结果与仿真结果吻合良好。通过眼图对新型EBG结构进行的仿真分析显示,新结构的信号完整性良好。     

红外与微波波段的周期电磁带隙结构

介绍了在红外及微波波段广泛应用的周期电磁带隙结构即频率选择表面的概念、特性、应用及研究进展，并对分析方法进行了综述。     

局部放电高性能电流传感器的设计

设计了一种基于罗氏线圈的高频电流传感器,对高频等效电路模型进行了理论计算,分析了影响传感器性能的各项参数.然后用Matlab软件对传感器进行仿真,总结参数变化对传感器性能影响的规律,最终确定适合本设计的传感器参数.最后对传感器加装处理电路,实现信号幅频响应通带到阻带快速降落的良好边界性能.测试结果表明,在特定频段内该传感器具有频带宽、灵敏度高及通带到阻带降落迅速等特点,性能良好.     

DGS结构参数对其反射特性的影响

设计了一种周期缺陷接地（DGS）结构,运用谱域法对所设计的DGS结构进行仿真分析。主要讨论单元尺寸a、基板介电常数、介质厚度、微带线宽度w以及狭缝的宽度g对阻带特性的影响。结果表明,单元尺寸、介电常数、介质厚度对阻带特性影响较大;微带线宽度w以及狭缝的宽度g对阻带特性的影响较小。带隙中心频率f0随着单元尺寸、介电常数、介质厚度的增大而减小。     

一种微带贴片天线RCS减缩新方法

为了减小微带贴片天线的雷达散射截面(RCS),利用电磁带隙结构(UC-EBG)的带阻特性,提出用UC-EBG代替普通金属作为微带贴片天线的地板．当天线工作频带内的电磁波入射时,UC-EBG地板呈现出带阻特性,不影响天线的正常工作;而在该频带以外,UC-EBG地板具有良好的带通特性,对入射电磁波起透射作用,从而可以达到减小天线带外RCS的目的．仿真和测量的结果吻合良好,证明了此方法的有效性．     

信号完整性中的串扰分析

当频率超过50 MHz时,印刷电路板板材的电参数,元器件在PCB板上的布局、高速信号的布线等因素都将影响系统性能,信号完整性（信号质量）已经成为高速数字PCB设计必须关心的问题之一.对信号完整性中的串扰进行了相关的理论分析,同时,采用Hyperlynx信号完整性工具进行了有效的仿真试验,验证了理论分析的正确性和相关性.     

一种新颖的微带线低通滤波器

针对传统微带线低通滤波器尺寸偏大、阻带较窄的问题,本文提出了一种新型结构滤波器.该滤波器由半圆型缺陷地结构(Semicircle Defected Ground Structure,S-DGS)单元和圆型阶梯阻抗并联枝节(Circle stepped-impedance shunt stubs,C-SISS)组成.文中首先分析了S-DGS和C-SISS结构对微带线低通滤波器带阻特性的影响,接着给出了微带线滤波器的等效电路模型.该滤波器3 dB截止频率为2.7 GHz,阻带为4～15.0 GHz,比传统DGS滤波器阻带拓宽了20%.测试结果与仿真结果吻合较好,验证了所设计滤波器的可靠性.     

Novel power plane with an electromagnetic bandgap structure for suppression of simultaneous switching noise

For ultra-wideband suppression of simultaneous switching noise between the power plane and the ground plane within the printed circuit board, a novel power plane with planar electromagnetic bandgap structures is proposed. When the suppression depth of the bandgap is -30dB, the width of the stop-band is 11.14GHz and the lower cut-off frequency is 0.28GHz. The simulated and measured results of the novel power plane with planar electromagnetic bandgap structures are in good ageement. The new EBG's stop-band is dramatically increased about 48.7％, with the lower cut-off frequency decreased to 0.46GHz compared with the L-bridged EBG structure with the same parameters. The signal integrity of the new EBG power plane can be improved by using differential transmission lines. This work is helpful for the EMC improvement of high speed digital circuits.     

A novel two-layer compact electromagnetic bandgap (EBG) structure and its applications in microwave circuits

Recently, photonic bandgap (PBG) structures have become one of the most interesting areas of research. These structures consist of one-, two- or three-dimensional finite periodically perforated dielectric/metallic material or ground planes that forbid the propagation of all electromagnetic waves within a particular frequency band (called the bandgap). This property permits additional control over the behaviour of electromagnetic waves. The research work was originally done in optical region, …     

Improved quasi-static effective medium model of the electromagnetic band gap (EBG) high-impedance surface

For the complex electromagnetic property of the electromagnetic band gap (EBG) high-impedance surface, an improved quasi-static effective medium model is proposed, which makes a quantitative relationship among the geometry, medium properties and the electromagnetic properties of the EBG high-impedance surface. The macroscopic interaction of the wave with the EBG high-impedance surface is equivalent to that of the wave with an effective medium when the wavelength is large compared with the dimension of each cell of the high-impedance surface. With the effective medium model proposed by quasi-static electromagnetic theory, designs of the high-impedance surface and its application system such as antenna system can be implemented separately. Some numerical simulations and experiments of practical high-impedance surfaces are given to illustrate the applications and validity of the proposed model.     

实时波前处理机中的同步开关噪声抑制

为解决自适应光学实时波前处理机中同步开关噪声问题,本文针对波前处理机电路特点,结合三维全波及电路仿真,对板上电源同步开关噪声来源进行了分析,并研究了去耦电容、分割电源平面及蘑菇型电磁带隙结构对噪声的综合抑制作用．研究结果表明,通过良好的器件布局、合理地进行电源平面分割及在关键器件周围加入去耦电容可降低平面间噪声,蘑菇型电磁带隙结构带宽高截止频率低的特性,具有良好的同步开关噪声抑制作用．针对实时波前处理机进行了仿真,采用系统级和板级噪声抑制措施后,在0～4GHz频带内噪声隔离度达到-52dB,满足处理机的电源完整性要求．     

宽带CIC抽取滤波器的一种改进方法

经典CIC抽取滤波器处理宽带信号时幅频响应不理想,满足带外衰减指标时,通带衰减过大,难以满足抗混叠性能要求.针对该问题,提出了一种改善性能的方法,在已有的分级抽取滤波器的基础上利用锐化技术提高滤波器阻带衰减,并利用补偿滤波器在采样率降低后对通带进行额外补偿,减少计算量的同时使带内更平坦.仿真分析表明,改进后的滤波器的通...     

曲面EBG结构表面波带隙特性研究

对3种典型EBG结构在曲面上表面波带隙特性进行了研究。利用悬置微带线法,分析了曲面EBG结构带隙特性与其结构参数及曲率的关系。结果表明,曲率对表面波带隙的影响不是太明显,只是带隙中心频率有稍微的下降,介电常数与介质厚度对带隙影响规律与平面上一致。这一结论对在圆柱共形天线上应用高阻表面结构有一定的指导意义。     

Impact of EBG Structures' Positions on the Performance of an EBG Antenna

Six circularly polarized patch antennas with electromagnetic band gap (EBG) arranged at different locations were studied. These EBG antennas were compared in terms of impedance bandwidth, axial ratio (AR) bandwidth and radiation patterns. When the EBG cells were placed closer to the edge of the substrate, the EBG antenna had a larger front radiation and a narrower bandwidth. Integrating the EBG cells closer to the center of the patch resulted in a wider impedance bandwidth, a wider axial ratio bandwidth and a decreased front gain.