Design and Characterization of a Dual-Band Impedance Transformer Based on an Embedded MTM-EBG

This paper presents the design of a dual-band impedance transformer using an embedded metamaterial-based electromagnetic bandgap structure (MTM-EBG). The MTM- EBG has a controllable bandgap with dispersive passbands on either side, which possess points of identical phase at arbirtary and designable frequencies. In this work, a MTM-EBG was designed to appear as a quarter wavelength 70.7 Ω microstrip transmission line to convert 50 Ω to 100 Ω at two frequencies: 2.4 GHz and 5.0 GHz, by using these points of equal phase. The resulting structure was then fabricated and tested, with experimental results demonstrating excellent agreement with the simulated data.