76 research outputs found
An application of learning stations in chemistry education The case of interactions between chemical species
A compact five-band SLR type metamaterial
In this paper, a novel single-loop resonator (SLR) type metamaterial topology is proposed with five distinct resonance frequencies placed within the frequency band from 2.8 GHz to 5.1 GHz displaying two -negative (ENG) and three -negative (MNG) bands. This new SLR unit cell is obtained by slightly modifying the geometrical structure of the square-shaped SLR that is recently reported in literature with only three resonances. Transmission and reflection characteristics of both standard square-shaped SLR and its newly modified version are simulated by two different full wave electromagnetic solvers, Ansoft's HFSS and CST Microwave Studio, to verify the accuracy of numerical results. Effective permittivity and permeability parameters of these metamaterial structures are retrieved from simulated complex scattering parameters to verify the presence of distinct ENG and MNG regions. E-field distributions are computed over the conductive strips to investigate the mechanism of resonances. Finally, effects of substrate permittivity and substrate thickness on the values of resonance frequencies are inspected parametrically for the novel SLR topology. © 2012 IEEE
Triangular-Shaped Single-Loop Resonator: A Triple-Band Metamaterial With MNG and ENG Regions in S/C Bands
A new metamaterial topology, called triangular-shaped single-loop resonator (SLR), is introduced with two distinct mu-negative (MNG) regions and one epsilon-negative (ENG) region over the S/C frequency bands. Transmission and reflection characteristics of the suggested subwavelength resonator are analyzed using full-wave electromagnetic solvers, Ansoft HFSS and CST Microwave Studio (MWS), to demonstrate the presence of four closely located resonance frequencies within the 3.3-5.1 GHz range. Effective permittivity and permeability parameters of the resulting composite medium are retrieved from simulated complex scattering parameters to verify the existence of fully developed MENG and ENG regions. Dependence of the resonance frequencies on the design parameters of the triangular SLR unit cell and on the presence of its gaps are also investigated in detail
Hybrid-shaped single-loop resonator: a four-band metamaterial structure
The aim of this reported work is to demonstrate the feasibility of a miniaturised four-band metamaterial resonator which has potential use in the design of multiband microwave devices such as four-band mobile phone patch antennas. The suggested resonator topology is called the hybrid-shaped single-loop resonator (HSLR) as its unit cell is formed by the combination of square-shaped and triangular-shaped sections of a single piece metal loop printed on a planar low-loss dielectric substrate. The performance of this novel four-band HSLR structure is investigated in comparison to the circular, triangular and square-shaped structures, which are recently reported double or triple band single-loop resonators. Simulations are performed using two different full wave electromagnetic solvers, HFSS and CST Microwave Studio, with excellent numerical agreement
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