Ultra-broadband cross-pyramid ionic liquid metamaterial absorber with 60° angular stability

Area of Science:

• Electromagnetic Metamaterials
• Materials Science

Background:

• Metamaterial absorbers are crucial for controlling electromagnetic waves.
• Developing broadband, polarization-insensitive, and wide-angle absorbers remains a challenge.

Purpose of the Study:

• To design and investigate a novel cross-pyramid metamaterial absorber.
• To evaluate its absorption performance, polarization, and angular stability, especially with ionic liquid.

Main Methods:

• Numerical simulations were performed to design the metamaterial absorber.
• The structure employed a cross-pyramid design with ionic liquid.
• Experimental validation was conducted to confirm simulation results.

Main Results:

• The absorber achieved over 90% absorption from 7.37-50.00 GHz (simulated) and 8.16-40.00 GHz (experimental).
• It exhibited polarization insensitivity and maintained high absorption at 60° incidence for both TE and TM modes.
• Stable performance was observed between 25 °C and 100 °C due to the ionic liquid's thermal stability.

Conclusions:

• The proposed metamaterial absorber exhibits excellent broadband, wide-angle, and polarization-insensitive absorption.
• The synergistic effect of the 3D impedance-gradient structure and ionic liquid contributes to efficient absorption.
• This design is a promising candidate for applications in electromagnetic shielding, stealth, and microwave devices.