ABSTRACT
The terahertz frequency band (0.1–10 THz) is a promising candidate to meet the high bandwidth demand set by the next generation of wireless communications systems. So far, most of the THz communication prototypes have been demonstrated for free-space wireless environments. Although wireless systems present many advantages such as convenience for mobile end-users and easier upgrades, many challenges remain. Notably, wireless links are prone to high alignment errors due to the highly directional nature of the THz beam. In turn, this requires complex beamsteering algorithms for reliable communication. This situation is even worse for non-line-of-sight links in indoor communications, for example. In this context, THz waveguides can be an additional tool in the design of future THz networks. They can offer reliable coupling to the receiver and transmitter by enclosing the THz radiation in a highly controlled propagation medium. They can span complex geometrical paths in both static and dynamic operations. Advanced THz waveguides can be used for real-time signal processing as an alternative to all-electronic solutions. In this chapter, we cover the most recent advances of THz waveguides applied to THz communications. We start by proposing several applications where THz waveguides/devices can be beneficial. Then, we present the inherent challenges related to the design of THz waveguides for communications. We then cover various types of THz waveguides developed in recent years. Finally, we show all-waveguide designs of passive/active components such as dispersion compensators, couplers, splitters, and add-drop multiplexers for signal processing.
