THz antennas design, developments, challenges, and applications: A review

Summary Terahertz (0.1–10 THz) wireless communication will be the future technology to reach a top‐notch data rate. THz is one of the most promising candidates for 6G systems because it provides enormous bandwidth, up to 100 GHz, and a massive data rate of up to 1 Tbps. THz antennas, antenna arrays, and MIMO antenna arrays in 6G are hot research topics for implementing 6G wireless communication systems. The 6G aims to continue to enhance the features of the 5G as it is capable of achieving the maximum high‐speed data rate, excellent reliable communication, massive connectivity, and very low latency connectivity. The 6G requirements need high‐gain antenna arrays and MIMO antenna arrays to combat the effect of atmospheric losses in high frequencies. An in‐depth discussion of the planar THz antennas that have been extensively used in THz applications like imaging, sensing, and Internet‐of‐Things (IoT) has been conducted. The study of the THz antennas, antenna arrays, and MIMO antennas on different conducting materials such as copper and graphene, which are designed on different dielectric substrates such as polyimide, quartz, liquid crystalline polymer, and polytetrafluoroethylene, has been carried out in detail. Metamaterial, photoconductive, plasmonic antennas, and THz beamforming are significant parts of THz communications. This paper also provides antennas and antenna arrays based on them.