An Ultrawideband Polarization-Insensitive Diffusion Metasurface Using Period Changed Unit Cell for RCS Reduction

Area of Science:

• Electromagnetics and Metamaterials
• Applied Physics
• Radar Technology

Background:

• Reducing the radar cross-section (RCS) is crucial for stealth applications.
• Ultrawideband (UWB) metasurfaces offer potential for broad-spectrum stealth solutions.
• Existing UWB metasurfaces often struggle with polarization insensitivity and complex designs.

Purpose of the Study:

• To develop a polarization-insensitive diffusion metasurface for ultrawideband RCS reduction.
• To propose novel coding elements based on period-changed unit cells and Minkowski loops.
• To demonstrate effective backscattering reduction in the 7.1 to 29.2 GHz range.

Main Methods:

• Design of a metasurface utilizing period-changed unit cells with metallic Minkowski loops as coding elements.
• Implementation of multilayer geometry and rotational symmetry for UWB and polarization-insensitive characteristics.
• Simulation, fabrication, and measurement of the proposed diffusion metasurface.

Main Results:

• Achieved a 180 ± 30° phase difference with consistent reflection amplitude across the UWB.
• Demonstrated polarization-insensitive behavior and UWB operation from 7.1 to 29.2 GHz (122% bandwidth).
• Experimental validation confirmed a 10 dB backscattering reduction over the entire UWB range.

Conclusions:

• The proposed diffusion metasurface effectively reduces RCS in an ultrawideband.
• The novel design using period-changed unit cells and Minkowski loops offers a promising approach for stealth technology.
• The polarization-insensitive and UWB characteristics make it suitable for diverse metallic object applications.