Low-profile metasurface-based dual-band graphene patch nanoantenna

This paper proposes a graphene patch antenna for dual-band operation while maintaining a low profile. The antenna consists of the metasurface-based 4 x 4 AMC configuration and the square graphene patch driven through the aperture coupling. The fundamental TM₁₀ mode of graphene patch excites the first resonance frequency, while the TM₁₀ and antiphase TM₂₀ modes of metasurface simultaneously excite the second wide frequency band. The first resonance frequency excited by the graphene patch can be reconfigured by varying the external DC bias voltage on the graphene patch. An equivalent circuit of antenna using lumped elements has also been proposed using a vector fitting algorithm. The proposed antenna with a profile height of $0.12{\lambda }_0$ (where ${\lambda }_0$ is free space wavelength) at a center frequency of 1.14 THz achieves the gain from 7.06 dB to 10.4 dB in the first band and an average gain of 10 dB in the second band.