Optimal Design of Miniaturized Reflecting Metasurfaces for Ultra-Wideband and Angularly Stable Polarization...

Area of Science:

• Electromagnetics and Metamaterials
• Applied Physics
• Microwave Engineering

Background:

• Metasurfaces offer unique electromagnetic properties.
• Achieving ultra-wideband (UWB) polarization conversion with angular stability is challenging.
• Existing polarization converters often have limited bandwidth or stability.

Purpose of the Study:

• To design and demonstrate an ultra-wideband linear polarization converter.
• To enhance angular stability of the polarization conversion.
• To develop a method for refining metasurface designs.

Main Methods:

• Design of a reflecting metasurface using miniaturized metallic elements.
• Optimization using a genetic algorithm (GA) to minimize co-polar reflection.
• Analysis of surface current distribution for design refinement.
• Full-wave simulations and experimental measurements for validation.

Main Results:

• Achieved a relative bandwidth of 102% (8.12–25.16 GHz) with GA optimization.
• Enhanced angular stability due to miniaturized unit cell and maximum periodicity.
• Refined design extended relative bandwidth to 117.8% with sub-wavelength periodicity (0.46 mm).
• Methodology for refining GA solutions based on surface current analysis proved effective.

Conclusions:

• The proposed ultra-wideband polarization metasurface demonstrates high performance and angular stability.
• Genetic algorithm optimization combined with surface current analysis is an effective design methodology.
• The developed polarization converter has potential applications in advanced electromagnetic systems.