Concurrent electromagnetic signature reduction and isolation improvement in a metasurface-integrated graphene-dielectric resonator MIMO tunable antenna for THz communication systems.

The design of a dual-port antenna with decreased RCS and circular polarization is presented in this study. A cylindrical silicon dielectric resonator is excited via an asymmetrical plus-shaped aperture-coupling device to produce circularly polarized radiation (3.45-3.85 THz). An EBG metasurface integrated on the underside of the substrate provides two significant advantages. First, it effectively reduces the monostatic radar cross-section (RCS), achieving values below -25dBsm. Second, it substantially improves the isolation between antenna ports, resulting in an isolation level that exceeds 25 dB. The suggested antenna works well in the 3.25-4.0 THz frequency band, according to CST/HFSS EM simulation. Throughout the operational band, the antenna exhibits steady radiation performance with a broadside peak realized gain of around 7.0 dBi. The suggested radiator is a feasible choice for THz radar and wireless transmission due to its directed broadside radiation characteristics and superior diversity performance.