Antenna array of circular patches on ferrite substrate

The steering properties of a circular patch antenna array fabricated on a yttrium-iron-garnet substrate containing 6/spl times/6 elements have been calculated. The formulation assumes the interaction between patch elements can be neglected. Also, the Voigt permeability is used as the effective permeability of the substrate. As such, the steering rate of the radiation beam at 12 GHz is found to be 1.67/spl deg//Oe at the broad side direction. Hexagonal ferrites are suggested to avoid permanent external magnetic bias.