A hybrid approach for optimizing medium frequency communication networks in coal mines

This work presents a hybrid approach using transmission line (TL) equations in conjunction with commercial method of moment (MoM) codes, to aid in efficient modeling of medium frequency (MF) propagation in coal mines. All local electromagnetic phenomena can be accurately modeled by strategic placement of full wave MoM sections near transmitting and receiving antennas. Meanwhile, ideal TL models are used to calculate loading and excitation of those MoM sections. In this way, communication networks can be modeled using a hybrid approach. The TL geometry of specific interest for this work is a single wire conductor positioned much less than one wavelength away from the floor/ceiling/wall of a mine. Previous work related to this geometry is summarized for approximate solutions of TL parameters. Examples are considered to demonstrate the capacity of the hybrid approach to optimize TL networks with significantly improved speeds.