Investigation of an Ultrawideband Circularly Polarized Highly Efficient Graphene Plasmonic THz Antenna for Ultrafast 6G Communications

ABSTRACT The manuscript presents the design and investigation of a graphene‐based ultrawideband (UWB) circularly polarized logarithmic spiral terahertz plasmonic antenna. Initially, it outlines the tunable conductivity and surface plasmon polariton (SPP) wave properties of single‐layer graphene (SLG) material. Further, the optimal design parameters are calculated for the logarithmic patch of the THz antenna targeting a wideband response centered at 1 THz over a silica/silicon dual substrate. The design is then modified by incorporating a few layers of graphene (FLG), leading to significant improvements in gain, directivity, efficiency, and other metrics. The antenna demonstrates impressive −10 dB impedance and 3 dB axial ratio bandwidths exceeding 126% (0.4–2 THz) due to its circular polarization‐supporting structure. It maintains stable performance characteristics, achieving a maximum gain of 3.9dBi along with radiation and total efficiencies of 91%. The group delay response (< 0.02 ns) from the time domain analysis of the designed UWB antenna transmitter receiver system verifies minimal pulse distortion. The performance of the proposed antenna makes it useful for ultrafast 6G THz communication applications.