A Wideband, Pressure-Driven, Liquid-Tunable Frequency Selective Surface

A wideband, liquid-metal-based, tunable frequency selective surface is presented. The structure consists of a periodic array of liquid mercury (Hg) volumes separated by gaps of mineral oil, encapsulated by an array of parallel polytetrafluoroethylene tubes. Tunability is achieved via pressure-driven fluidic control over the respective volumes of Hg and oil. A tuning range of 4.08-16.96 GHz (122.4% fractional bandwidth) is demonstrated.