Optically reconfigurable unit cell for Ka-band reflectarray antennas

Abstract

A new method for achieving amplitude reconfiguration in a reflectarray antenna is presented in this Letter. An individual unit cell is a compact multilayer structure, including a silver inkjet-printed layer for rapid prototyping of the reflectarray. A small infrared light emitting diode (IR-LED) illuminating a silicon wafer provides the reconfiguration in the system. Various illumination intensities of the IR-LED allow for differing magnitudes of reflection from the unit cell. This provides the potential for radiation pattern tapering or amplitude modifications of the gain of the reflectarray. Simulation and measurement results for a single unit cell are presented here, with the matching between measurement and simulation also allowing for the change in the values of conductivity of the silicon to be extracted.