A switchable terahertz reflectarray consisting of crossed metal dipoles set in a graphene grid

Abstract

A switchable reflectarray antenna composed of crossed metal dipoles mounted on a graphene grid is proposed for switchable radiation patterns at 1 THz. For an individual radiating element, the single graphene square loop works together with the metal dipoles to offer a corresponding phase response. As an entirety, the grid formed by the attached graphene loops is connected to a particular bias electrode for switchable operation. Taking the practical manufacturing technique into account, the graphene-oxide-silicon structure is used as the bias electrode. The simulated phase response shows that a phase range over 330° is obtained by changing the dimension of the metal dipoles from 11 μm to 70 μm. The simulated field distributions and radiation patterns demonstrate that the proposed structure can deflect the normal incident plane waves in the predesigned direction when it is biased in a specific state. Once the bias is set to zero, incident plane waves are scattered into different directions.