Optical Control of Reconfigurable Antennas and Application to a Novel Pattern-Reconfigurable Planar Design

This paper discusses techniques for optical control of reconfigurable antennas using commercially available devices. These techniques are applied to a pattern-reconfigurable planar antenna that integrates optical control circuitry to switch folded microstrip radiators arranged in each of the quadrants. By switching between the microstrip elements, the designed antenna can generate a single omnidirectional or four directional patterns, maintaining good impedance matching within the 2.4 GHz WiFi band. We investigated two possible strategies for optical control: 1) p-i-n photodectors based switching, and 2) phototransistor controlled RF p-i-n diodes switches. Extended numerical and experimental analysis was carried out for the latter technique, discussing advantages and limitations when employed as RF switch on reconfigurable antennas. Finally, measurements of input impedance and radiation patterns were collected to validate the proposed optically controlled antenna design and compared to standard electronic control.