S-parameters analysis of waveguide bend with metamaterial

Metamaterials are materials built in laboratories that have a negative refractive index. They have been applied in many different areas, such as antennas, super lenses, sensors and cloak of invisibility. In this paper a metamaterial is applied in waveguides, in order to achieve better transmission rates for the electromagnetic waves propagating in those devices. The metamaterial is obtained using split-ring resonators printed on dielectric substrates, and the waveguide's simulation was performed using CST Studio Suite simulator. The effects of those metamaterial structures on the reflection and transmission of the bend waveguide are evaluated by scattering parameters. This article proposes the application of metamaterials in two different scenarios, defined by the position of the metamaterial inside the bend waveguide. Through simulations, the power flow behavior, the loss reduction and increase in the transmission rate inside the waveguide were observed. The insertion of SRR metamaterials allowed the structure to efficiently operate on frequencies above 8 GHz, which is unfeasible for the conventional waveguide.