A thin wire array and magnetic host structure with n<

Abstract

Construction of artificial media possessing a negative index of refraction can be simplified by using a nonconducting ferrimagnetic host medium to provide a negative permeability and an array of conducting wires to provide a negative permittivity. The interaction between the ferrimagnet and the wire array, which destroys the negative permittivity of the wire array, can be overcome by cladding the wires with an insulating, nonmagnetic jacket. Calculations of the propagation constants and transmission coefficients for a square array of cladded wires in a ferrimagnetic host are presented. The calculations are near exact for wavelengths significantly greater than the lattice parameter of the wire array. For wires a few microns in diameter, a lattice constant of 0.8mm, and an appropriate ferrimagnetic host in a biasing magnetic field, a transmission band 0.5GHz wide centered near 16GHz exhibits a negative index of refraction. Losses in the ferrimagnet and impedance mismatch to vacuum limit the peak transmission amplitude ratio through a slab 3.0cm thick to ≈3%.