Eliminating Ground Reliance in Reflective Metasurfaces for Anomalous Reflections

Area of Science:

• Optics and Electromagnetism
• Metasurface Technology

Background:

• Reflective metasurfaces (RMs) are crucial for redirecting signals and overcoming line-of-sight (LoS) blockages.
• Conventional RMs require metallic ground planes, limiting their angle range and increasing dielectric losses.

Purpose of the Study:

• To develop a novel RM design that eliminates the need for a metallic ground plane.
• To demonstrate high-performance beam reflection with improved directivity and wider operating bandwidth.

Main Methods:

• Introduced an open-edge loop structure as the unit cell for the metasurface.
• Investigated three distinct open-edge loop-based RMs under varying incidence and reflection angles.
• Utilized experimental verification to confirm simulated beam reflection characteristics.

Main Results:

• Developed RMs function as 'wave benders,' transforming incident waves into endfire reflected beams (90°).
• Achieved a directivity improvement of approximately 5 dBi compared to ground-based designs.
• Experimental results confirmed beam reflection across a wide bandwidth (26–33 GHz).

Conclusions:

• This work presents the first high-performance reflective metasurface design independent of a metallic ground plane.
• The novel open-edge loop structure offers a promising alternative for advanced beam manipulation applications.