Tunable ferrite-dielectric metamolecule with Fano resonance

Xiaobo Wang,Haohua Li,Ji Zhou

doi:10.1063/1.5089578

Abstract

Actively controllable material properties are desirable for applications in materials science and microwave engineering. We design and fabricate a magnetically-coupled metamolecule with ferrite for X-band microwave frequencies that shows tunable responses to external magnetic fields. When compared with the metamolecule’s magnetic Mie resonance, superior field sensitivity is observed in the vicinity of the Fano resonance through analysis of the transmission spectra. The mechanism is investigated by emulating the field distributions, and the phenomenon is attributed to specially coupled magnetic dipoles. The simulation results are verified experimentally. This work substantiates the metamaterial’s enhanced electromagnetic properties for potential application to tunable microwave devices.

Highlights

Electromagnetic metamaterials are artificial media with tailorable physical properties that arise from subwavelength metallic or dielectric resonator structures.1,2 Among the different types of metamaterials, Mie-based dielectric metamaterials are able to support dipoles or more complex modes.3 Without conductive currents or capacitance gaps, these materials exhibit low heat loss and can realize isotropy,3,4 which enables fabrication of intriguing metadevices for microwave and photonics applications
A sharp Mie resonance dip from the dielectric component emerges at 10.624 GHz, while no resonance exists for the ferrite in this frequency range
Two resonance dips emerge for the metamolecule at 10.172 GHz and 10.488 GHz, which are both in the vicinity of the Mie resonance of the cube

Summary

Introduction

Electromagnetic metamaterials are artificial media with tailorable physical properties that arise from subwavelength metallic or dielectric resonator structures. Among the different types of metamaterials, Mie-based dielectric metamaterials are able to support dipoles or more complex modes. Without conductive currents or capacitance gaps, these materials exhibit low heat loss and can realize isotropy, which enables fabrication of intriguing metadevices for microwave and photonics applications. Electromagnetic metamaterials are artificial media with tailorable physical properties that arise from subwavelength metallic or dielectric resonator structures.. Metamaterials were initially proposed to realize negative refraction or left-handed material properties that cannot be found in natural materials, but they have been used to acquire or enhance specific existing characteristics, including Fano resonances.. Fano resonances occur commonly in quantum systems and produce asymmetric line-shapes. These resonances are closely related to symmetry-breaking, and are commonly explained by the destructive coupling of a discrete state and the continuum near the resonance frequency.. Using the coupled oscillators model as a classical analogy, Fano resonances have been achieved and widely investigated in metamaterials and in metamolecules with distorted structures.. High-performance sensors and switches are obtainable when the Fano interference is introduced

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Results

Conclusion