Path Loss and Surface Impedance Models for Surface Wave-Assisted Wireless Communication System

Surface wave-assisted wireless communication systems have recently emerged as a promising complementary solution for creating a smart radio environment, particularly in the context of beyond-fifth generation (5G) and sixth generation (6G) networks. Unlike traditional approaches that rely solely on space waves or use passive elements on a large surface to reflect space waves, the incorporation of surface waves can effectively address challenges such as blockage and severe path loss, which are prevalent at extremely high frequencies, including millimeter wave (mmWave) and terahertz (THz) bands. Recent advances in metasurface properties have enabled the propagation of electromagnetic waves on a surface without re-radiation. Motivated by these developments, in this paper, we develop a path loss model and two surface impedance models for surface wave-assisted wireless communication systems. We demonstrate that the signal-to-noise ratio (SNR) of this system can be significantly higher than that of traditional wireless communication systems because the path loss for a surface wave is proportional to the propagation distance, whereas the path loss for a space wave is proportional to the square of the propagation distance. Furthermore, we explore how the metasurface should be designed in terms of its materials and structures, considering that the incident space wave must be aligned with Brewster’s angle to excite a surface wave.