Terahertz tunable filter based on metasurface

Abstract

The invention relates to a terahertz tunable filter based on a metasurface. The filter comprises a plurality of filter units which are arranged in an array, each filter unit comprises a substrate dielectric layer, a phase change material layer and a split-ring resonator unit which are stacked in sequence, and each split-ring resonator unit comprises a cylindrical ring body and a cross-shaped unitwhich is horizontally placed in the cylindrical ring body. When electromagnetic waves are incident, a large number of charges are gathered on the two sides of the opening perpendicular to the direction of the electric field due to the action of the electric field and are equivalent to capacitance, the cylindrical ring body is equivalent to inductance, an electromagnetic resonance loop is formed, obvious resonance is generated near the incident frequency of 670 GHz, and then the electric field intensity of the corresponding position is large. When the phase change material layer is subjected tothermal / electrical stimulation, the current amorphous state mode is converted into the crystalline state mode, and the dielectric constant of the material characteristics is obviously changed, so that the transmission peak is subjected to blue shift, and the tunability is realized.

Description

technical field [0001] The invention relates to the field of electromagnetic filtering, in particular to a metasurface-based terahertz tunable filter. Background technique [0002] Metamaterial is a kind of artificial composite material, which is composed of natural materials arranged periodically in sub-wavelength unit structure, and has extraordinary electromagnetic properties that natural materials do not have, such as negative magnetic permeability, negative refractive index, negative permittivity, etc. . Metasurfaces are formed on the basis of metamaterials. Different from metamaterials, metasurfaces are a two-dimensional planar structure that overcomes the challenge of processing three-dimensional structures of metamaterials. Therefore, metasurface technology has been an attractive research frontier in recent years, and researchers have designed a series of metasurface-based devices, such as frequency selective surface (FSS), split resonator ring (SRR) and other type...

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Problems solved by technology

However, it is difficult to achieve tuning using these methods, such as the high drive voltage of MEMS that is difficult to interface with CMOS control circuits; the design and fabrication of control mechanisms required for physical tuning are complex, and they need to be considered in simulation; liquid crystal It is difficult to realize integrated design, so that the entire device is integrated and chip-based; semiconductors require a large bias voltage, which obviously does not meet our requirements

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