Design of generalized invisible scatterers

Area of Science:

• Electromagnetics
• Applied Physics
• Signal Processing

Background:

• Inverse scattering problems are complex, often requiring iterative solutions.
• Designing objects with specific scattering responses is crucial for applications like cloaking.
• Traditional methods struggle with strongly scattering objects and achieving precise angular control.

Purpose of the Study:

• To develop a nonlinear signal processing method for designing strongly scattering objects with a defined angular response.
• To complement inverse scattering by utilizing k-space design and cepstral filtering.
• To demonstrate the creation of objects with enhanced forward scattering and suppressed scattering in other directions, including electromagnetic cloaks.

Main Methods:

• Applying nonlinear signal processing techniques to object design.
• Combining k-space design methods with cepstral filtering.
• Modifying the k-space of an object's angular spectrum to achieve desired scattering behavior.
• Mapping secondary source distributions to permittivity distributions for strong scattering scenarios.

Main Results:

• A method to design permittivity distributions for controlled scattering responses was developed.
• Objects were successfully modified to enhance forward scattering and suppress scattering in other directions.
• Simulations confirmed the method's effectiveness in achieving desired scattering properties.
• The designed structures function as effective electromagnetic cloaks.

Conclusions:

• The developed nonlinear signal processing method offers a novel approach to designing scattering objects.
• Cepstral filtering is effective in handling strong scattering and mapping source distributions to permittivity.
• The method provides a powerful tool for creating metamaterials with tailored electromagnetic properties, such as cloaking devices.