Properties Prescribing and Control of Direct and Inverse Opal Metamaterials Doped with Spinels, Used for Mems |
| D. Ionescua, M. Kovacib
a``Gh. Asachi'' Technical University of Iasi, Department of Telecommunications, 700506 Iasi, Romania bPolitehnica University Timisoara, Department of Communications, 300223 Timisoara, Romania |
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| Properties prescribing and control of the photonic metamaterials operating in microwave fields represents the main task of our study. Magnetic-dielectric composites of opal (SiO2 matrices or similar), with insertions of ferrite spinels in the inter-sphere voids (5÷60 nm inclusions, 3-7 vol.%) with insular random/periodic distribution have been considered. Samples have been analyzed by structural simulation, placed inside a rectangular waveguide, mode TE10, at frequencies of 20÷40 GHz, for determining the resonance and antiresonances of the electromagnetic quantities that describe the material behavior. Variations of these quantities have been obtained by changing the structural parameters of the samples and optimal sets of values have been determined for each composite. The domains above the resonant/antiresonant frequency, in which the effective permittivity, respectively permeability are negative have been controlled in order to obtain a wider propagation band. A structure with periodic regular distribution of the inclusions was studied, realized by introducing pre-polarization periodical UV fields (λ=200 nm), 2D applied (in cross). Particles molecular coating was applied for maintaining the inclusion positions. The propagation band became tunable by ferrite control and we report a band increasing of about 40% to 200%, depending on the ions nature in the ferrite and influenced by the structure capacity of interacting with the microwave field. |
DOI:10.12693/APhysPolA.135.849 topics: photonic metamaterials, opal, ferrite inclusions, modulated structure, propagation band control |