Experimental demonstration of electrically controllable photonic crystals at centimeter wavelengths

Electrically controllable photonic crystals have been fabricated by inserting p-i-n diodes in two-dimensional metallic lattices. A first structure uses a square lattice of thin and discontinuous metallic wires. A second structure is fabricated using stacks of printed circuits with metallic strips. The p-i-n diodes are soldered along the different metallic wires or strips. The crystals have been characterized between 1 and 20 GHz. We show that they can be operated as wideband switchable electromagnetic windows with high transmission or reflection contrast between on and off states. A ∼25 dB transmission modulation is reported within the first transmission band of a two-period crystal. We also show that the switching domain and modulation rate can be varied with a separate bias control for each crystal plane. Finally, the distance between crystal planes is used to tune the operating frequency range.