摘要 |
<p>An electronically tuneable surface. The surface comprises: a conductive sheet comprising at least one opening; and a biasing circuit. The biasing circuit comprises first and second conductors, separated from the conductive sheet by a dielectric, and arranged at mutually opposing sides of the opening such that each conductor is capacitively coupled to the conductive sheet at the respective side of the opening. The conductors define a gap between them corresponding to the opening. The biasing circuit also comprises an electrical control element bridging the gap, connected to the first and second conductors. When the element is in a first state, the surface exhibits a first frequency transmission characteristic with respect to incident electromagnetic radiation, and when the element is in a second state, the surface exhibits a second, different characteristic.</p> |