Electric and magnetic dipole couplings in split ring resonator metamaterials

In this paper, the electric and the magnetic dipole couplings between the outer and the inner rings of a single split ring resonator （SRR） are investigated. We numerically demonstrate that the magnetic resonance frequency can be substantially modified by changing the couplings of the electric and magnetic dipoles, and give a theoretical expression of the magnetic resonance frequency. The results in this work are expected to be conducive to a deeper understanding of the SRR and other similar metamaterials, and provide new guidance for complex metamaterials design with a tailored electromagnetic response.

Effect of Cavity Dimensions on TE_01δMode Resonance in Split-Post Dielectric Resonator Techniques

The effects of cavity dimensions on the resonance frequency and resonance strength of the TE01δmode in split postdielectric resonator (SPDR) technique are investigated by using full-wave simulations. The results of simulations provide guidance for adjusting the dimensional parameters of the set-up to ensure that a strong TE01δ resonance mode is excited. The scaled designs of SPDR fixtures for operation at frequencies that are most important for applications are presented. These designs employ two sets of dielectric resonators (DRs) that can be fabricated from the standard ceramic materials. In addition, it is demonstrated that the resonance frequency of the TE01δ mode in the fixture can be tuned by adjusting the gap of the split DR.

Terahertz Transmission Properties of Split Ring Resonator Arrays

The transmission properties of double-ring split ring resonator(SRR) arrays and closed ring resonator arrays are measured using terahertz(THz) time-domain spectroscopy. This technique allows for the simultaneous measurement of the amplitude and phase of the transmission coefficient as a function of frequency. The ability to directly measure the phase spectrum is expected to be important in characterizing potential negative index media. In the employed experimental geometry, THz pulses are normally incident on the arrays. Thus, the magnetic field lies in the plane of the arrays and cannot contribute to the magnetic resonance of the SRR. However, it is found that the electric field, when appropriately polarized, can couple to the magnetic resonance. Shifts in the resonance properties with changes in the SRR dimensions and the substrate medium are measured, the results of which are consistent with theory.

Photocatalytic seawater splitting by 2D heterostructure of ZnIn_(2)S_(4)/WO_(3) decorated with plasmonic Au for hydrogen evolution under visible light

Photocatalytic H_(2) evolution from seawater splitting presents a promising approach to tackle the fossil energy crisis and mitigate carbon emission due to the abundant source of seawater and sunlight on the earth.However,the development of efficient photocatalysts for seawater splitting remains a formidable challenge.Herein,a 2D/2D ZnIn_(2)S_(4)/WO_(3)(ZIS/WO_(3))heterojunction nanostructure is fabricated to efficiently separate the photoinduced carriers by steering electron transfer from the conduction band minimum of WO_(3) to the valence band maximum of ZIS via constructing internal electric field.Subsequently,plasmonic Au nanoparticles(NPs)as a novel photosensitizer and a reduction cocatalyst are anchored on ZIS/WO_(3) surface to further enhance the optical absorption of ZIS/WO_(3) heterojunction and accelerate the catalytic conversion.The obtained Au/ZIS/WO_(3) photocatalyst exhibits an outstanding H_(2) evolution rate of 2610.6 or 3566.3μmol g^(-1)h~(-1)from seawater splitting under visible or full-spectrum light irradiation,respectively.These rates represent an impressive increase of approximately 7.3-and 6,6-fold compared to those of ZIS under the illumination of the same light source.The unique 2D/2D structure,internal electric field,and plasmonic metal modification together boost the photocatalytic H_(2) evolution rate of Au/ZIS/WO_(3),making it even comparable to H_(2) evolution from pure water splitting.The present work sheds light on the development of efficient photocatalysts for seawater splitting.

Analysis of Metamaterial Cloaks Using Circular Split Ring Resonator Structures

A novel microwave cloak using circular split ring resonator(SRR)based metamaterial structure has been proposed in this paper.The cloak which operates at a frequency of 10.6 GHz is composed of cylindrical dielectric sheets printed with circular split ring resonators of spatially varying and anisotropic material properties.The article also focuses on the phenomenon of resonant splitting in circular SRR microwave cloak.A detailed analysis of various linear metamaterial arrays and their response has also been elucidated.

Effects of oblique incidence on terahertz responses of planar split-ring resonators

Effects of oblique incidence of terahertz waves on the response of planar split-ring resonators are investigated, both experimentally and by simulation. It is found that the incident angle dependent phase delay and coupling conditions of neighboring split-ring resonator （SRR） units play important roles and greatly change both the transmission and reflection spectra for the resonant feature of linear charge oscillations. Our results show that the SRR structure-supported magne- toelectric couplings at oblique excitation are trivial and can be ignored. A highly symmetric response is found in the cross-polarization effects, which may manifest the bianisotropic properties of the SRR system but this needs further study.

Design of Multi-band Small Antenna Based on Single Split-Ring Resonator

To use the single split-ring resonator （SRR） as a basic unit cell for small antenna with multi-band frequency response is proposed. The structure of antenna is consisted of a single spilt-ring resonator and a coupled microstrip line. The designed antenna is numerically optimized with CST Microwave Studio. The radiation properties of the antenna show that there are three frequency bands among which two bands are 1.3 GHz and 2.1 GHz ultra-widehand （UWB）, respectively, where Sll is less than - 10 dB. The gain at every frequency for the multi-hand antenna is above 2.6 dBi, and it increases monotonously with the frequency in the two UWB.

Band-stop optical nanofilters with split-ring resonators based on metal–insulator–metal structure

Novel band-stop filters with circular split-ring resonators based on the metal-insulator-metal （MIM） structure are presented, with their transmission properties of SPPs propagating through the filter simulated by the finite-difference time-domain （FDTD） method, The variation of the gap of the split ring can affect the transmission characteristics, i.e., the transmission spectrum of SPPs exhibiting a shift, which is useful for modulating the filter. Linear and nonlinear media are used in the resonator respectively. By varying the refractive index of the linear medium, the transmission properties can be changed obviously, and the effect caused by changing the incident intensity with a nonlinear medium is similar. Several resonant modes that are applicable can be enhanced by changing the position of the gap of the split ring. Thus, the transmission properties can be modulated by adjusting the size of the gap, varying the refractive index, and changing the incident intensity of the input light. These methods may play significant roles in applications of optical integrated circuits and nanostructural devices.

Expanding the bandwidth of planar MNG materials with co-directional split-ring resonators

An effective approach to expand the bandwidth of negative permeability of small-sized planax materials is proposed. Based on qualitative analysis of equivalent circuit models, the fractional bandwidth of an μ-negative （MNG） material is expanded from 3.53% up to 12.87% by adding split-ring resonators （SRRs） and arranging them by proposed steps. Moreover, the experimental results validate the effectiveness of bandwidth-expanding methods, which is promising for the extensive application of metamaterials in the microwave field.

Permittivity Measurement of Low-Loss Substrates Based on Split Ring Resonators

In this paper, we present the complex permittivity measurement of low-loss substrates based on a microstrip-line-excited split-ring resonator (SRR). Permittivity of an unknown substrate is calculated based on the change in oscillation frequency of SRR caused by the material-under-test (MUT) above the SRR. Theoretical analysis and results of the simulations and experiments demonstrate the microstrip-line-excited SRR can be used to effectively improve measurement sensitivity. Simple equations for measurement of low-loss substrates using SRR are proposed and experimentally verified.

Interleaved-Connected Split Planar Resonant Inductor Design in 1 kV SiC LLC Converters

Design method of split planar resonant inductor in 1 kV SiC logical link control(LLC)converter is proposed,which ensures the converter power density of 93.59 W/in^3 and peak efficiency of 95.73%.Split resonant inductor helps to provide symmetrical resonant current by symmetrical impedance,and improves the distortion of resonant current,which ensures the efficiency of the whole converter.An interleaved winding connecting scheme improves the power density of the planar magnets,which contributes to power density improvement.Design method and calculation process of such split planar resonant inductor are provided.To verify the feasibility of the proposed design method,a 1 kV/48 V 6.6 kW,210 k Hz SiC LLC prototype was built,and the experimental results are given.

Resonant Peak Splitting for Ballistic Conductance in Two-Dimensional Electron Gas Under Electromagnetic Modulation

By developing a transfer-matrix method,the resonant peaks splitting of ballistic conductance are investigated into the two-dimensional electron gas system with both electric and magnetic modulations of nanoscale periods.It is found that there exists the n-fold resonant peak splitting for ballistic conductance through n perpendicular magnetic barriers to n electric barriers.With a combination of m magnetic barriers and n electric barriers by increasing the amplitude of electric field,the folds of the splitting would shift from m- to n-1.

Miniaturized multi-band antenna using deformed splot ring resonator

A 48 mm x 60 mm x 1 mm miniaturized multi band antenna based on deformed split ring re sonators was presented. The antenna was consisted of a micro strip line and a deformed split square ring. Its/S11/parameters were determined through numerical simulation and experimental measure ment within three working bands of 2.6 GHz to 3. 0 GHz, 3. 9 GHz to 4. 4 GHz and 5.2 GHz to 5. 8 GHz and the results showed that the parameters within all the bands were less than 10 dB. The gain at every frequency for the antenna was above 2.2 dB and it increased monotonously with the frequency from 5. 5 GHz to 7. 0 GHz.

Electronic Resonant Splitting in a Nanostructure with Periodic Magnetic-Electric Barriers

In this letter, the transmission probability and the conductance of the ballistic electron are studied in a nanostructure with the periodic magnetic-electric barriers. We find that the resonant splitting increases with the number of periods increasing, so the number of the resonant peaks increases and the peaks become sharper. For the m-th periodic magnetic-electric barriers tunneling the splitting is （m - 1）-fold.

Very Compact Bandstop Filters Based on Miniaturized Complementary Metamaterial Resonators

In this paper, a design of very compact microstrip bandstop filters based on complementary split ring resonators (CSRRs) is proposed. Two techniques of metamaterial miniaturization are used to optimize the physical and electrical size of the CSRR. The bandstop filter is produced by an array of miniaturized loaded CSRRs etched on the center line of a microstrip. The size of the proposed filter, is as small as 0.58 cm2, and its electrical length is very small with only 0.08 λ0), compared to a conventional bandstop filter, a miniaturization of a factor 5 while the bandstop performance is maintained. A very good agreement obtained between the measurement and the simulation results.

非线性谐振无线电能传输系统频率分裂特性

针对由于频率分裂现象导致无线电能传输系统传输效率降低的问题,采用非线性谐振拓扑替代传统线性谐振拓扑抑制频率分裂进行了研究。首先通过A参数矩阵法得出了求解高阶系统传输效率公式理论方法,并推导了非线性传输系统的效率公式;分析了非线性谐振传输系统抑制频率分裂现象的原理,在系统产生频率分裂现象的情况下将非线性电感并入次级线圈,可以改善系统的传输特性。并通过仿真测试频率分裂现象对于非线性传输系统的影响。结果表明:在相同频率条件下,非线性传输系统可以推迟传输系统临界耦合状态的出现,且对抑制频率分裂现象具有明显的效果。

基于实稳定方法的原子核单粒子共振相对论Hartree-Fock模型

利用坐标空间的实稳定方法,在相对论Hartree-Fock(RHF)理论框架下发展了原子核单粒子共振态结构模型.具体以^(120)Sn的低激发中子共振态为例,探讨了交换项在影响共振能量、宽度以及自旋-轨道劈裂等性质中的作用.相较于一般的相对论平均场(RMF)理论,RHF中交换项的引入改变了核介质中有效核力的动力学平衡机制,进而影响共振态单粒子势的描述.对于一般的宽共振态,这可能导致相对更低的共振能量和更小的共振宽度.此外,对^(120)Sn共振态中νi_(13/2)与νi_(11/2)自旋伙伴态,还分析了交换项对其自旋-轨道劈裂的相关效应.与束缚态情形相比,共振态中自旋伙伴态的波函数可能存在显著区别,单粒子有效势与能量也相应发生改变.结果表明,不仅自旋-轨道相互作用,单粒子有效势中其他成分也是影响共振态自旋-轨道劈裂的重要因素.

基于慢波基片集成波导的小型化移相功分器

针对移相器和功分器的功能融合设计,提出了一种基于慢波基片集成波导(Slow-Wave Substrate Integrated Waveguide,SW-SIW)的小型化移相功分器,两个输出分支等长带宽,可实现30°相移量.其中一个输出分支通过基片集成波导(Substrate Integrated Waveguide,SIW)实现,而另一个输出分支将互补开口谐振环(Complementary SplitRing Resonator,CSRR)加载在上层金属表面,代替传统SIW连续的金属表面,该CSRR由经典CSRR结构演变而来,同时为了降低由CSRR加载所造成的相位上的不稳定,在CSRR内部添加金属化通孔,实现SW-SIW,使得截止频率和相速度降低.测试结果表明,移相功分器在9.0~11.8 GHz频带范围内反射系数|S11|小于-10 d B,相对工作带宽为26.9%,插入损耗小于1.3 d B.两个输出端口的相位差稳定在30°±3°,幅度差小于1.4 d B,实现了等功率分配.所设计的移相功分器具有较小的尺寸和低制造成本,适合应用在相控阵天线中.

高速互连PCB的材料电磁表征方法研究

随着数据传输速率的不断增加,对高速互连的信号完整性设计和优化变得至关重要。在高速通道设计的各个方面中,我们通过对现有的方法进行综述来着重介绍准确的PCB材料电磁表征这一关键问题,并对于提取PCB材料特性,如介电常数、损耗正切以及铜表面粗糙度的各种方法进行分类。首先,这些方法分为两大类:①对原始介质材料进行表征的技术;②适用于一般由玻璃纤维和树脂材料混合而成的PCB材料的表征方法。在每个类别中,简要描述了几种常用技术,并进行了优缺点的比较和讨论。基于传输线的方法的挑战和局限性在这里尤为重要,因为相关的材料特性提取程序在工业中已经是常规操作。此外,特别是在数十吉赫兹的频率范围内,典型铜箔表面粗糙度对准确材料表征的影响也被考虑。本文旨在通过总结和比较提供PCB材料表征方法的全面概述和分析。