Mechanically Tunable MTM-EBG-based Bandstop Filter

Tunable filters are increasingly popular components in telecommunication systems as they are flexible and adaptable to changing conditions. A tunable bandstop filter based on the recently proposed metamaterial-based electromagnetic bandgap structure (MTM-EBG) is demonstrated here that relies on a single mechanically tuned element. This structure, without any tuning mechanism attached, has a simulated 10-dB transmission absolute bandwidth (ABW) of 225 MHz centered at 4.18 GHz. It is then made tunable by placing a dielectric plate on the surface of the MTM-EBG and varying the position of the plate; this changes the reactive loading and subsequently shifts the response. Using a plate of RO4350B, a tuning range from 3.43 to 4.05 GHz with a 13.6% variation in ABW is demonstrated in simulation.