Reconfigurable Intelligent Surface for Highly Efficient Electromagnetic Functionality

Abstract

Controlling the environment in a wireless communication system is difficult. But Re-configurable Intelligent Surfaces (RIS) paves a path for it by applying the concept of meta-surfaces. In this paper, we propose a means by which radio-frequency waves could be controlled electronically using a re-configurable meta-surface, which consist of 3 layers of metal over substrate. Each surface is an array of 8 cells and it is designed to operate in the 3-4 GHz. The ON and OFF state can be ideally achieved using any RF switches like PIN diodes. In this paper, the concept is proved using metal strips between the cells for ON and removing it for OFF state. In ON state, the meta-surface is designed to reflect the EM wave completely, just like a perfect metal. In OFF state, the waves in the designed frequency band passes through the structure. The simulation and measured results shows a 200 MHz transmission bandwidth. We have fabricated the designed meta-surface and verified the transmission and reflection properties in a S -band wave guide.