Guided electromagnetic waves in a curved rectangular mine tunnel

Abstract

The transmission of VHF electromagnetic waves in a curved mine tunnel is analyzed using an idealized model in a cylindrical geometry. The tunnel cross section is assumed to be rectangular and the broad curved walls are imperfectly reflecting. The computations of the modal characteristics are facilitated by using a modified Airy function approximation of the rigorous cylindrical wave functions. The results indicated that the curvature of such tunnels will seriously increase the attenuation of the dominant low‐order modes that are used for communications.