Magneto-dielectric substrate influence on the efficiency of a reconfigurable patch antenna

In this paper we investigate the influence of dielectric and magnetic losses of an Epoxy bonded Yttrium Iron Garnet (YIG-Epoxy) composite substrate on the performance of a reconfigurable microstrip patch antenna. The antenna under investigation is a microstrip patch antenna printed on a 60/40 w/w% YIG-Epoxy composite substrate and controlled by an externally applied DC magnetic field. It is observed that high dielectric losses of the composite substrate can dramatically deteriorate the radiation efficiency of the proposed antenna in the demagnetized state, while in the magnetized state the magnitude of the resonance linewidth (ΔH) of the composite substrate is the main parameter responsible for the reduction or improvement of the radiation efficiency. Considerable effort has been made to fabricate a YIG-Epoxy substrate with improved properties regarding dielectric loss tangent and magnetic resonance linewidth. The prototyping and characterization of a reconfigurable patch antenna on the “improved” YIG-Epoxy substrate is also presented.