High-Speed RF Switch for EMI Shielding

"The development of fast-switching coatings and devices for broadband (2-18 GHz) transmission modulation of RF radiation is proposed. The modulation is obtained with intrinsically conducting polymers (ICPs) that are switched between microwave transmittingand opaque states by controlling the oxidation state of the ICP. The primary RF switching elements will be thin-films of conductive polymers formed by electrochemical deposition on patterned, metallized substrates. The switches will be fabricated in devicestructures that employ polymeric ion conductors and highly reversible charge-balancing counterelectrodes that are essential for reliable, multicycle performance. The Phase I program will demonstrate the fabrication of small devices suitable forcharacterization of RF transmission modulation in waveguide instrumentation. Optimization of device performance and durability through control of morphology, density, and composition of the conductive polymer film will be demonstrated. Devices will bechallenged by thermal cycling, thermal shock, mechanical stress, and salt spray (ASTM B117) exposure. The Phase II effort would focus on transition of the coatings to substrate materials and geometries suitable for the subsystems relevant to the Navy.Methods for fabricating the devices on substrates with compound curvature and strategies for obtaining rapid switching in large-area applications are proposed. Conductive polymer switches have applicat