Dual-port tunable graphene–silicon ceramic-based hybrid filtering antenna with circular polarization characteristics in THz regime

In this article, a two-port antenna with tunable filtering and circular polarization features is designed and discussed. A graphene-based metasurface is suspended over the dual-port radiator to convert the linear polarized waves into circular polarized waves. Dual stubs loaded microstrip line and a slot fed silicon ceramic show filtering features outside the operating band. The optimized results confirm that the proposed radiator works between 2.41 and 2.8 THz with 3-dB down axial ratio from 2.41 to 2.61 THz. The value of coupling between the ports is less than − 20 dB. The value of gain in between the operating band is 5.0 dBi, while it is less than − 15 dBi outside the working band. A coating of graphene over the ceramic and graphene-based metasurface creates the tunable features in the reflection coefficient, gain and axial ratio parameters of the designed antenna. Stable far-field parameters confirm that the designed antenna effectively works for different wireless applications in the THz frequency band.