Integrated terahertz transceiver front-end utilizing spatiotemporal modulation

The paper proposes a method for developing spatiotemporally modulated structures operating at THz frequencies. In this technique, electromagnetic waves propagating inside microwave waveguides modulate the chemical potential of a graphene sheet both temporally and spatially. The modulated graphene sheet interconnects these waveguides with a plasmonic waveguide carrying a THz wave. This approach has been used to create an integrated device that encapsulates all components of a THz transceiver front-end in a single unit. The device leverages the extraordinary features of spatiotemporally modulated structures, such as nonreciprocal response and frequency mixing, to integrate all functionalities of a THz transceiver front-end. We have implemented a leaky-wave antenna, mixer, and duplexer with beam steering capabilities, all within a spatiotemporal graphene-based structure. The performance of the device is investigated both analytically and numerically in transmit and receive modes. Additionally, the modulating waveguides have undergone both electromagnetic and thermal numerical simulations to ensure they can handle the power required for efficient modulation of graphene without overheating, which could hinder their performance.