Joint Channel and Antenna Modeling for Magnetic Induction Communication in Inhomogeneous Media

Magnetic induction communication (MIC) demonstrates high penetration efficiency and low propagation loss in extreme environments. It is used in underground and underwater environments to enable critical applications that cannot be achieved by using terrestrial wireless techniques. This article studies the channel and antenna modeling for MIC in inhomogeneous environments, where a transmitter and a receiver are in two different media. This problem finds a large number of practical applications such as communicating with wireless sensors in the soil, water, walls, and the human body using a wireless device in the air. This article develops a joint channel and antenna model considering the inhomogeneity of the surrounding environments. An exact full-wave model and a near field approximation model are developed and evaluated to show the characteristics of this novel wireless technique as well as the limitations of existing solutions. Using the communication with underground sensors as an example, the results show that the path loss of MIC strongly depends on the propagation media which is drastically different from electromagnetic wave-based wireless communications in terrestrial environments. Also, we find that the MIC channel in inhomogeneous media exhibits non-reciprocity due to different transmission coefficients through the boundary. Moreover, the boundary can be neglected when the carrier frequency is sufficiently low. The developed model provides a tool to design wireless sensor networks in inhomogeneous extreme environments.