Polydimethylsiloxane Based Reconfigurable Intelligent Surfaces Loaded Flexible Antenna for Pattern Reconfigurable Applications

This study proposes the design of Polydimethylsiloxane (PDMS) based semi-transparent flexible antenna system for omni-directional to directional pattern reconfigurable applications. The system comprises of a compact antenna resonating at 3.5 GHz which is loaded with an reconfigurable intelligent surface (RIS) controlled by PIN diodes. Both antenna and RIS are made up of 1mm thick PDMS substrate, a highly flexible and transparent material, while radiator of proposed system is made using copper with a thickness of 0.035mm. The RIS backed antenna offers omni-directional radiation pattern when all switches are off-state, resulting in in-activation of RIS. On the other hand, a broadside radiation pattern is achieved when the switches are turned ON, corresponding to activation of RIS. Conformal analyses are also carried out by cylindrical bending across the X- and Y-axis, along with that the SAR analysis are performed to validate the suitability of proposed work for on-body applications.