THz Antennas: Applications and Challenges—A Review

An overview of the latest advances in promoting terahertz (THz) antenna performance is given in this work, along with an explanation of the necessity of addressing issues related to high loss and poor manufacturing accuracy, particularly in the context of small sizes within high-frequency THz bands. This investigation emphasizes the pivotal significance of terahertz (THz) antennas in the transfer and receipt of electromagnetic waves within the context of burgeoning THz systems, by leveraging their inherent advantages such as small form factor, broad frequency bandwidth, and high data rates. Furthermore, the research delves into the exploration of various conducting materials, including copper and graphene, as well as diverse dielectric substrates like polyimide and quartz. Given its special qualities, it has drawn more and more interest in a variety of applications. The terahertz frequency band, which is normally between 0.1 and 10 THz, corresponds to where terahertz antennas are intended to function. They play a crucial role in transmitting and receiving terahertz signals for various applications. Besides, antenna arrays involve the use of multiple antennas working together as a system. In the context of terahertz, antenna arrays can enhance directivity, gain, and overall performance. Furthermore, Multiple-Input Multiple-Output (MIMO) technology involves using multiple antennas for transmitting and receiving data simultaneously. MIMO systems are employed to improve communication performance by increasing data rates and reliability. In addition, the choice of materials and substrates is critical in the design of THz antennas. Different materials can affect the performance of antennas, and researchers might explore various substrates to optimize characteristics. This paper will delve into the existing challenges and obstacles faced in the development and implementation of THz antennas. Challenges might include issues related to fabrication, efficiency, signal propagation, and integration into practical systems. This comprehensive investigation encompasses THz antennas, antenna arrays, and MIMO antennas, aiming to elucidate their unique characteristics and performance attributes across different materials and substrates. Finally, in the latter section of this paper, the persisting challenges in the realm of terahertz (THz) antennas are introduced.