Tunable microwave metasurfaces for high-performance operations: dispersion compensation and dynamical switch.

Area of Science:

• Metasurfaces
• Electromagnetic wave manipulation
• Microwave optics

Background:

• Metasurfaces offer advanced light control but passive designs suffer from intrinsic dispersion, limiting performance across frequencies.
• Existing metasurfaces rely on passive meta-atoms with fixed responses, hindering broadband applications and dynamic tunability.

Purpose of the Study:

• To develop a novel scheme for microwave metasurfaces that overcomes the limitations of passive designs.
• To demonstrate a tunable metasurface with wide frequency band operation and switchable functionalities.
• To enable dispersion-corrected and dynamically controllable electromagnetic wave manipulation.

Main Methods:

• Integration of tunable meta-atoms incorporating varactor diodes into metasurface designs.
• Precise control of the dispersive response of individual meta-atoms via external voltage.
• Experimental demonstration of a tunable gradient metasurface and its dynamic switching capabilities.

Main Results:

• The tunable metasurface achieved single-mode, high-efficiency operation over a wide frequency band, unlike passive counterparts limited to a single frequency.
• Demonstrated dynamic switching of metasurface functionality from specular reflection to surface-wave conversion.
• Showcased dispersion-corrected performance across a broad frequency range.

Conclusions:

• The proposed scheme effectively resolves dispersion limitations in metasurfaces using tunable meta-atoms.
• The developed metasurfaces offer unprecedented control over electromagnetic waves, enabling both broadband operation and dynamic functionality.
• This approach paves the way for advanced, reconfigurable microwave devices and systems.