Anomalous microwave reflection from a metal surface induced by spoof surface plasmon

The reflection of X-band microwaves （8-12 GHz） from a metallic aluminum （A1） surface with groove grating corrugations was investigated experimentally. It was shown that the reflection of p-polarization is much less than the microwave reflected from the corresponding area of an unruled Al surface, with selective wavelength. The experimental results demonstrated that the anomalous microwave reflection is strongly associated with the excitation of spoof surface plasmons at the Al air interface by the surface grating coupler. This near-total absence of reflected microwaves is similar to the famous Wood＇s anomaly in the optical regime and is of fundamental importance to the applications of spoof surface plasmons in the microwave regime.

Wideband polarization-independent anomalous reflection metasurface with multiple resonance modes

An ultra-thin metasurface is proposed to realize wideband polarization-independent anomalous reflection. The sub-wavelengthresonator can produce different resonance modes, which are the result of the combined effect of dielectric and the metallic structure.The gradient metasurface is done by six discrete orientation of the local sub-wavelength resonator which provides a phase gradient.The simulation and measured results show that 9 GHz bandwidth of the anomalous reflection is achieved.

A review of anomalous refractive and reflective metasurfaces

Abnormal refraction and reflection refers to the phenomenon in which light does not follow its traditional laws of propagation and instead is subject to refraction and reflection at abnormal angles that satisfy a generalization of Snell’s law.Metasurfaces can realize this phenomenon through appropriate selection of materials and structural design,and they have a wide range of potential applications in the military,communications,scientific,and biomedical fields.This paper summarizes the current state of research on abnormal refractive and reflective metasurfaces and their application scenarios.It discusses types of abnormal refractive and reflective metasurfaces based on their tuning modes(active and passive),their applications in different wavelength bands,and their future development.The technical obstacles that arise with existing metasurface technology are summarized,and prospects for future development and applications of abnormal refractive and reflective metasurfaces are discussed.

Reflected Wavefront Modulation with Phase Array by Using Acoustic Metasurface

Acoustic metasurface has attracted increasing attention due to the ability of manipulating the transmitted and reflected phase of waves to generate various acoustic functionalities with planar layer of sub-wavelength structure.We design an acoustic metasurface with a semi-closed and nested slotted tube array,and it possesses the capacity of modulating the reflected phase with sub-wavelength thickness (about λ/23).The reflected phase shifts can be obtained from 0 to 2π by different rotation angles of internal slotted tubes.The theoretical results agree well with the numerical results by a finite element method.The results show that some excellent wavefront manipulations are demonstrated with the phase array by using acoustic metasurface such as anomalous reflection and sub-wavelength flat focusing.The design may offer a path for acoustic manipulation and promote the potential applications of acoustic metasurface in low frequency noise control,acoustic imaging and cloaking.