113. LEAKAGE FIELD PROFILES BY NONLINEAR METAMATERIAL ABSORBERS
Name: Sanghoon Kim
Grad Year: 2016
Modern microwave technology has been broadly developed in antenna and communication fields, as well as radar and other applications. Therefore, modern electronics and sensitive antennas are easily exposed to interference from external microwave waves. Specifically, when a high power microwave impinges on a conductive shielded enclosure, surface currents can cause interference which leads to faults or malfunctions of the enclosed sensitive electronics. Moreover, the high power surface currents are able to leak inside through gaps or such openings in the conductive shielding. Even if an aperture is electrically small, it can effectively work as a slot antenna that can allow radiation inside. Here, we introduce a novel concept of a power dependent switchable metamaterial absorber based on nonlinear circuits deployed on a high impedance surface. The metasurface includes a pair of diodes which transform it from a low loss to high loss state when incoming high power waves. The proposed metasurface allows low power signals for communications to propagate but strongly absorbs high power signals for triggering the faults of the electronics inside to protest against damage. From simulations and experiments we verify that the nonlinear metasurface has two distinct states controlled by the incoming signal powers. Specifically, we mainly demonstrate that it inhibits the propagation of large signals and dramatically decreases the field that is leaked through an opening in a conductive enclosure. In this poster, we will show that it can limit the amount of electromagnetic leakage through a gap in a metal enclosure by applying the nonlinear metamaterial absorbers, demonstrating that it can be used for practical applications.
Industry Application Area(s)
Aerospace, Defense, Security | Electronics/Photonics | Materials