A Wideband Unit Cell Design for RIS-Aided Ku-Band LEO Satellite Communications

This work proposes a wideband 1-bit unit cell design for reconfigurable intelligent surface (RIS)-aided Ku-band low earth orbit (LEO) satellite communications. The unit cell features stacked patch structures positioned on two different layers. The stacked structures facilitate a double resonant behavior, enabling a wideband performance. The structures are designed on a multi-layer Taconic RF35 substrate. A PIN diode is employed to alter the reflection coefficient of the unit cell, effectively allowing the structure to shift the phase of the incoming EM waves by <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$180^{\circ}\pm30^{\circ}$</tex> over the 10 GHz – 14 GHz frequency band while maintaining a low reflection loss. Through simulations, we validate the capability of the proposed unit cell, when arranged as an RIS array, to steer and focus the incoming EM beam towards different angles.