<italic>THzPrism</italic>: Frequency-Based Beam Spreading for Terahertz Communication Systems

With large available bandwidths, Terahertz (THz) band communication has been envisioned as a key technique to satisfy the increasing demand for ultra-high-speed wireless communications. To overcome severe path loss of THz signals, large antenna array based beamforming, i.e., directional communication, is required for THz communications. Beamforming increases distance coverage, but it significantly reduces angular coverage, which severely limits the efficiency and flexibility of THz systems. In this letter, a novel phased array architecture called THzPrism is designed to conduct beamforming for THz systems. The key idea of THzPrism is to insert several true time delay devices in a phased array so as to achieve frequency-based beam spreading. As a result, THzPrism can significantly enlarge angular coverage while maintaining the distance coverage for THz systems. Both theoretical analysis and numerical results are conducted to validate the effectiveness of THzPrism.