Binary geometric phase metasurface for ultra-wideband microwave diffuse scatterings with optical transparency

Area of Science:

• Metamaterials and Nanophotonics
• Electromagnetic Wave Scattering
• Optical Engineering

Background:

• Metasurfaces offer advanced control over electromagnetic (EM) wave interactions.
• Reducing backward scattering is crucial for target stealth and signal integrity.
• Improving the working bandwidth of scattering reduction techniques remains a significant challenge.

Purpose of the Study:

• To propose and demonstrate an ultra-wideband metasurface for backward scattering reduction.
• To achieve high optical transparency alongside significant scattering reduction.
• To explore diffuse scattering as a mechanism for stealth applications.

Main Methods:

• Design of a binary geometric phase metasurface utilizing multi-layered reflective meta-structures.
• Implementation of geometric rotation to achieve out-of-phase counterparts.
• Characterization of polarization-insensitive wave-diffusion properties through simulation and experimental fabrication.

Main Results:

• Achieved approximately 10 dB scattering reduction over an ultra-wide frequency band (3.5 GHz to 16.6 GHz).
• Demonstrated a fractional bandwidth of 130% for backward scattering reduction.
• Experimental results validated the simulated performance, confirming the metasurface's efficacy.

Conclusions:

• The proposed metasurface effectively reduces backward scattering through diffuse scattering mechanisms.
• The design offers a polarization-insensitive and ultra-wideband solution with high optical transmittance.
• This technology holds potential for practical applications such as window stealth.