Low-Frequency Broadband Bandgap of a Tunable Metamaterial Beam with Electromagnetic Resonators: Numerical and Experimental Study

This paper reveals effective low-frequency bandgap broadening mechanisms over wide ranges by integrating tunable electromagnetic resonance units into a metamaterial beam structure. The structure consists of faceplates, internally arranged electromagnetic resonators (EMRs), and inter-faceplate support structures. Through energy method analysis of infinite beams and finite element modeling of metamaterial structures, this study establishes dispersion behavior and wave transmittance characteristics. The results show that the control of the bandgaps in the metamaterial beam can be achieved by adjusting the voltage of the EMRs. By employing different groups of control voltages, multi-frequency coupling among the resonators can be achieved, resulting in a tunable low-frequency broadband bandgap. Finally, experimental studies are conducted to validate the obtained results. This research provides valuable insights for the design of actively controlled metamaterial structures.