Electromagnetic response and homogenization of grids of ferromagnetic microwires

This contribution presents an analytical formulation for the electromagnetic response of grids of ferromagnetic microwires, where the electromagnetic fields produced by the structure are found by means of the local field method. In addition, a circuit analogy is introduced for a better understanding of the grid response, where a single ferromagnetic microwire is modeled as an impedance-loaded wire, and the transmission-line approach is used for the whole grid. Moreover, the homogenization of the structure is considered to provide more physical insight into internal polarizations of the grid. Contrary to the previous experiments of left-handed transmission in grids of ferromagnetic microwires, it is found that such structures can be modeled as artificial dielectric slabs with a frequency dispersive permittivity.