Vanadium Dioxide Energy Selective Surface for Nonlinear Wavefront Manipulation

A novel vanadium dioxide (VO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>) energy selective surface was designed, fabricated, and tested for operation in X-band. VO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> is an insulator-metal-transition phase-change material that exhibits a sharp conductivity change at a temperature of 68°C or with a large electric field. The periodic surface utilizes the nonlinear behavior of VO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> to allow low-power waves to be collected but reject nearby in-band or near-in-band interference sources. The energy selective surface enables a more robust receive chain for high sensitivity receive systems. The four-legged loaded slot energy selective surface has a 3-dB transmission bandwidth between 9.5-10.5 GHz, in the low power state, and a greater than 30-dB rejection (0.1% of power transmitted) in the high-power state. The updated octagonal design has a 3-dB transmission bandwidth between 9-11.5 GHz, and a greater than 25-dB rejection. Fabrication of the new design is ongoing, and measurement results will be presented at the conference.