A THz graphene-on-hBN stack patch antenna for future 6G communications

Wireless communications have progressively tapped into higher frequency bands seeking higher bandwidth and integration, opening the door to short-range applications such as data kiosks, wireless chip interconnects, or intra-body networks. Graphene antennas working at terahertz (THz) frequencies are theoretically smaller in size compared to metallic antennas working at the same frequency, pushing the boundaries of integration further. However, such miniaturization ability has not yet been experimentally validated. This study presents the first working THz antenna based on chemical vapor deposited (CVD) monolayer graphene. The antenna, placed on the hexagonal Boron Nitride (hBN) buffer layer, comprises a multi-layer stack of two graphene patches separated by a thin dielectric, resulting in a significantly more efficient antenna than a standard one-layer graphene antenna. The proposed antenna shows a resonance frequency of 250.7 GHz and a gain of -9.5 dB. The miniaturization and frequency tuning capabilities of graphene antennas make the proposed graphene stack patch antenna a valuable asset for 6G short-range communications. Additionally, the proposed graphene stack antenna can be integrated in the back-end-of-line with CMOS manufacturing techniques and applied to future THz communication systems.