Versatile metasurface platform for electromagnetic wave tailoring

Abstract

The emergence of metasurfaces provides a novel strategy to tailor the electromagnetic response of electromagnetic waves in a controlled manner by judicious design of the constitutive meta-atom. However, passive metasurfaces tend to perform a specific or limited number of functionalities and suffer from narrow-frequency-band operation. Reported reconfigurable metasurfaces can generally be controlled only in a 1D configuration or use p-i-n diodes to show binary phase states. Here, a 2D reconfigurable reflective metasurface with individually addressable meta-atoms enabling a continuous phase control is proposed in the microwave regime. The response of the meta-atom is flexibly controlled by changing the bias voltage applied to the embedded varactor diode through an elaborated power supply system. By assigning appropriate phase profiles to the metasurface through voltage modulation, complex beam generation, including Bessel beams, vortex beams, and Airy beams, is fulfilled to demonstrate the accurate phase-control capability of the reconfigurable metasurface. Both simulations and measurements are performed as a proof of concept and show good agreement. The proposed design paves the way toward the achievement of real-time and programmable multifunctional meta-devices, with enormous potential for microwave applications such as wireless communication, electromagnetic imaging, and smart antennas.

Metasurfaces for Far-Field Radiation Pattern Correction of Antennas under Dielectric Seamed-Radomes

“…The metasurface's unit-cell, also referred to as meta-atom, can be carefully designed to obtain specific amplitude and phase profiles, thus enabling a plethora of applications, ranging from polarization converters [9,10] to absorbers [11][12][13][14][15], as well as wide-angle impedance matching structures [16,17], imaging holography [18][19][20], complex waves generation [21] and many more [22]. More recently, programmable metasurfaces have attracted huge interests due to their versatility in performing different functionalities [23]. Self-adaptively reprogrammable functionalities without human participation have been fulfilled by a metasurface by integrating an unmanned sensing feedback system [24].…”

Electronic Beam-Scanning Antenna Based on a Reconfigurable Phase-Modulated Metasurface

“…Thanks to these structures, new properties, such as anomalous reflection and refraction, have been proposed and demonstrated [7][8][9]. Metasurfaces also facilitated the generation of complex wavefronts, such as Airy beams [10,11], vortex beams carrying orbital angular momentum (OAM) [12,13], Bessel beams [14][15][16] and image holograms [17][18][19][20][21]. In the field of antennas, metasurfaces have aided in developing different topologies of structures.…”

“…In order to reach real-time control of the electromagnetic properties, as required in reconfigurable antennas, lumped electronic components are loaded in meta-atoms composing the metasurfaces [29]. Several types of components have been considered for reconfigurability mechanism, such as liquid crystals [30,31], PIN diodes [32,33], varactor diodes [15,34], MEMS [35] and graphene [36]. The electronic elements are used to tune the resonant properties of the meta-atom, thereby helping to dynamically tailor electromagnetic wavefronts.…”

Reconfigurable terahertz metasurfaces coherently controlled by wavelength-scale-structured light

“…Reconfigurability of microwave metasurfaces is achieved by connecting active electronic components, such as varactors, diodes or transistors, to each meta-atom comprising the metasurface. A voltage applied to the electronic component in each meta-atom tunes its electromagnetic response and controls the local phase imparted to an incident microwave field [ 22 ], [ 23 ], [ 24 ], [ 25 ]. At higher frequencies, it becomes increasingly challenging to integrate electronic devices with structures comprising the metasurface.…”