Thin Film Reconfigurable Intelligent Surface for Harmonic Beam Steering

TL;DR

This paper presents a cost-effective, flexible, and reconfigurable thin film RIS using inkjet printing on PET, capable of harmonic beam steering for advanced communication and sensing applications.

Contribution

It introduces a novel, easily fabricated 1-by-4 RIS with integrated control, enabling dynamic harmonic beam steering without complex manufacturing.

Findings

Successful beam steering of harmonics demonstrated

Low-cost inkjet printing method validated

RIS operates on flexible PET substrate

Abstract

This letter explores an implementation of a novel thin film 1-by-4 reconfigurable intelligent surface (RIS) designed for future communication and sensing scenarios. Utilizing cost-effective inkjet printing methods and additive manufacturing, our approach significantly simplifies the RIS construction process and reduces production costs. The RIS, fabricated on a flexible and lightweight polyethylene terephthalate (PET) substrate, integrates antennas, switching circuitry, and a microcontroller unit (MCU), without a ground shield. This setup enables individual and simultaneous control of each RIS element, manipulating the captured carrier signal by reflecting and refracting its dominant harmonics. Beams of the harmonics can be steered to multiple desired directions at both front and back sides of the surface. Measurement results of the beam steering show that the RIS has the potential to enable RIS-aided communication and sensing applications.