Impact of a conducting medium on the coupling of meta-atoms

We have studied analytically, numerically and experimentally the effect of conducting material upon the mutual inductance between two coils yielding thereby the attenuation of magnetoinductive (MI) waves. It is shown among others that the expression for plane wave attenuation, used in the literature, has only limited validity. Our results will be relevant for the design and optimisation of MI waveguide links in conducting media in general and particularly when the attenuation is caused by soil conductivity. The results will also help medical diagnosis in problems where parts of the human body are imaged.