Multi-functional metasurface architecture for amplitude, polarization and wavefront control

Abstract

Metasurfaces (MSs) have been utilized to manipulate different properties of electromagnetic waves. By combining local control over the wave amplitude, phase, and polarization into a single tunable structure, a multifunctional and reconfigurable metasurface can be realized, capable of full control over incident radiation. Here, we experimentally validate a multi-functional metasurface architecture for the microwave regime, where in principle variable loads are connected behind the backplane to reconfigurably shape the complex surface impedance. As a proof-of-concept step, we fabricate several metasurface instances with static loads in different configurations (surface mount capacitors and resistors of different values in different connection topologies) to validate the approach and showcase the different achievable functionalities. Specifically, we show perfect absorption for oblique incidence (both polarizations), broadband linear polarization conversion, and beam splitting, demonstrating control over the amplitude, polarization state, and wavefront, respectively. Measurements are performed in the 4-18 GHz range inside an anechoic chamber and show good agreement with theoretically-anticipated results. Our results clearly demonstrate the practical potential of the proposed architecture for reconfigurable electromagnetic wave manipulation.

XR-RF Imaging Enabled by Software-Defined Metasurfaces and Machine Learning: Foundational Vision, Technologies and Challenges

“…The fabrication requirements of the proposed SDMs involve the capability of manufacturing high-quality multiplemetallization boards using high-frequency, low-loss specialty substrates. In addition, we need high-aspect ratio through vias and blind vias with uniform metal plating and good electrical conductivity characteristics in order to minimize the resistive loss experienced by the loop currents excited in the unit cell [104]. Finally, the assembly of the controller chips is based on closely-space solder balls to enable the dense packing of unit-cells/controllers.…”