  The microwave properties of glass-fibers reinforced polymer composite
embedded with an orthogonal array of Fe77Si10B10C3 microwires have been
investigated. The composites containing orthogonal wire arrays display a
remarkable transmission window in the frequency band of 1 to 6 GHz under zero
external magnetic field indicating an intrinsic double-negative-index
characteristic. The polymer matrices have proved to exert a synergistic effect
on the microwave properties, which is responsible for the disappearance of the
transmission windows when Ek is perpendicular to the glass fiber direction. The
plasma frequency of the orthogonal microwire array composite is higher than
that of the parallel microwire array with identical wire spacing; this could be
attributed to the enhanced microwire-wave interaction induced by the axial
electrical components on the additional layer of perpendicular wires. All these
features make this new kind of orthogonal microwire composites promising for
potential cloaking and sensing applications.
