Graphene-Based Reconfigurable Intelligent Meta-Surface Structure for THz Communications

Abstract

In this paper, a graphene based reconfigurable intelligent metasurface structure is proposed for terahertz (THz) communication applications. The proposed structure consists of multilayer unit cells with a graphene radiating patch. By using different values of biasing voltages, the chemical potential (µc) of the graphene is changed which leads to have different reflected phases. Based on this property we are able to create different reflected phase distributions within the full structure metasurface array which can be controlled by coding pattern in processing units. The proposed unit cell can provide an acceptable reflection characteristic around 4.35 THz. In addition, by changing the biasing voltage, four states are generated which can transmit 1-bit and 2-bits data. The proposed metasurface structure has small size and high flexibility in controlling radiation patterns. The simulated results such as reflected phase distributions and reconfigurable radiation patterns show the effectiveness of the proposed design for THz communication.

Coverage Analysis of Reconfigurable Intelligent Surface Assisted THz Wireless Systems

“…which leads to (45), given at the top of the next page. Finally, by applying (3) in ( 21), we get (17). This concludes the proof.…”

“…Proposition 1. The outage probability of the multi-RISempowered THz wireless system can be evaluated as in (17), given at the top of the next page. In (17), γ s is the transmission SNR multiplied by the deterministic path-gain, i.e.,…”

“…Note that from (17), it becomes evident that hardware imperfections set a limit to the maximum allowed spectral efficiency of the transmission scheme. In more detail, since the spectral efficiency, p, is connected with the SNR threshold through…”

“…Inspired by this, a great amount of effort has been put on designing RIS that operate in the THz band [14]- [17] as well as theoretically characterizing the corresponding system performance [18]- [20]. In particular, in [14], a vanadium dioxide (VO 2 )-based multi-functional RIS was presented, while, in [15], a large-scale RIS that employs arrays of complementary metal-oxide-semiconductor (CMOS)-based chip tiles operating at 0.3 THz was reported.…”

“…The design of a graphene-based RIS structure with beam steering and focusing capabilities at 4. 35 THz was discussed in [17]. From the performance analysis points of view, the error performance of RIS-empowered THz wireless satellite systems in the presence of antenna misalignment was studied in [18].…”