Design of a Reconfigurable MIMO System for THz Communications Based on Graphene Antennas

Abstract—Based on the properties of graphene nano-patch antennas, we propose a reconfigurable multiple-input mul-tiple-output (MIMO) antenna system for Terahertz (THz) communications. First, the characteristics of the graphene are analyzed and a beam reconfigurable antenna is designed. The beamwidth and direction can be controlled by the states of each graphene patch in the antenna. Then the path loss and reflec-tion models of the THz channel are discussed. We combine the graphene-based antenna and the THz channel model, and propose a new MIMO antenna design. The radiation directions of the transmit antennas can be programmed dynamically, leading to different channel state matrices. Finally, the path loss and the channel capacity are numerically calculated and compared with those of the Gigahertz (GHz) channel. The results show that for short range communications, the proposed MIMO antenna design can enlarge the channel capacity by both increasing the number of antennas and choosing the best channel state matrices. Index Terms—Graphene antenna, reconfigurable multiple-input multiple-output (MIMO) system, terahertz (THz). I