Uneven-Layered Coding Metamaterial Tile for Ultra-wideband RCS Reduction and Diffuse Scattering

Area of Science:

• Electromagnetics
• Materials Science
• Metamaterials

Background:

• Radar cross section (RCS) reduction is crucial for stealth applications.
• Traditional methods often suffer from limited bandwidth.
• Diffuse scattering aims to redirect electromagnetic waves in multiple directions.

Purpose of the Study:

• To propose a novel uneven-layered coding metamaterial tile.
• To achieve ultra-wideband RCS reduction and diffuse scattering.
• To validate the proposed design through simulations and measurements.

Main Methods:

• Designing a metamaterial tile with two types of square ring unit cells of varying thickness.
• Utilizing a 180° reflection phase difference between unit cells for wideband operation.
• Encoding the tile and its 90-degree rotation as binary elements ('0' and '1').
• Optimizing phase distribution for diffuse scattering.

Main Results:

• Achieved -10 dB RCS reduction from 6.2 GHz to 25.7 GHz (4.15:1 ratio bandwidth) at normal incidence.
• Demonstrated simultaneous reduction in monostatic and bi-static RCS.
• Exhibited a diffuse scattering pattern with four strong lobes deviating from the normal direction.
• Simulated and measured results showed good agreement.

Conclusions:

• The proposed uneven-layered coding metamaterial tile effectively reduces RCS over an ultra-wideband.
• The design enables significant diffuse scattering, enhancing stealth capabilities.
• This approach offers a promising solution for broadband RCS reduction and diffuse scattering applications.