Designing and analysis of non-symmetric dual layer CRLH metamaterial

Abstract

The underlying study investigates the artificial metamaterial designing of non-symmetric dual layer combination on the same substrate for the negative characteristics of refractive index, permittivity and permeability. The design is instigated with the investigation of single and dual layers metamaterial design for single or double negative behavior. Apart from the parametric study, the dispersion diagrams of the layers are also evaluated for gap and gapless transactions from left hand to right hand behavior. The combination of symmetric and non-symmetric layers is also analyzed for behavior change in material properties. The permittivity and permeability of the designed non-symmetric dual layer metamaterial are negative up to 10 GHz and are positive above 10 GHz. Moreover, the left and right hand impedance also remains unchanged and matched with that of free space impedance (377 Ω) with a fractional bandwidth of 50%. Hence, the designed material acts as a double positive material for high frequencies above 10 GHz and double negative material for low frequencies below 10 GHz. The design is verified using circuit modeling and full wave electromagnetic simulations. The results obtained are authenticated using the free space measurement method.