A novel tunable high impedance surface electromagnetic band gap metamaterials for RF and microwave applications

This paper presents a novel varactor based electronically tunable high impedance surface electromagnetic band-gap (HIS-EBG) metamaterial. The proposed structure is based on two-layer mushroom-like HIS-EBG ground plane, in which by controlling the DC bias voltage on the varactors, the effective capacitance can be adjusted which alters the resonance frequency. To assess the electromagnetic (EM) wave suppression property the structure is incorporated, as the ground plane, in a microstrip transmission line and it is experimentally characterized over the 500 MHz-10 GHz frequency band. Numerical simulations of the transmission coefficient for the whole microstrip system were performed. Both the simulation and measurement results are compared.