The steering properties of a circular patch antenna array fabricated o
n a yttrium-iron-garnet substrate containing 6 x 6 elements have been
calculated, The formulation assumes the interaction between patch elem
ents can be neglected, Also, the Voigt permeability is used as the eff
ective permeability of the substrate, As such, the steering rate of th
e radiation beam at 12 GHz is found to be 1.67 degrees/Oe at the broad
side direction, Hexagonal ferrites are suggested to avoid permanent e
xternal magnetic bias.