Optically controlled frequency selective surface for millimeter-wave applications

In this paper, an optically controlled millimeter-wave frequency selective surface using high resistivity silicon as tunable substrate is designed and tested. It is shown from measured results, the transmission performance of FSS at resonant frequency is tuned from −1.02dB to −16dB by light illumination. The photoconductive characteristic of silicon in millimeter wave region is studied. It is shown from the measured results that the insertion loss of silicon at 110GHz is 0.0005dB without light illumination. However, its transmission coefficient decreases to −25dB at 110GHz and −45dB at 320GHz under 500mW IR light illumination.