A Compact Dual-Band EMI Metasurface Shield With an Actively Tunable Polarized Lower Band

In this letter, a compact tunable metasurface for dual-band electromagnetic interference (EMI) shielding is being proposed. In particular, Jerusalem crosses intersecting diagonally are used to design and synthesize a prototype metasurface shield. It has been shown that a finite 4 × 3 array of the Jerusalem crosses can be used for EMI shielding in the 900 MHz and 1.8-GHz GSM bands. Then, to develop an active shield that is tunable, varactor diodes were attached to the dual-band metasurface. Measurements have shown that the lower band of the metasurface can be changed (tuned) with various control voltages. Finally, simulation, equivalent circuit computations, and measurements are shown to agree.