An antenna array with a high division ratio Wilkinson power dividers

This article presents the design and measurement results of a three element antenna array that uses two high division ratio Wilkinson power dividers. This solution provides a beam that is tilted from the ground while maintaining side lobes level below -20dB. The current distribution for such an antenna pattern has very steep amplitude differences that are hardly realizable in the conventional microstrip technology. Because of that, power dividers were designed using Wilkinson topology with the defected ground structure (DGS). DGS provides an additional inductance component that increases the microstrip line´s characteristic impedance value. It allows to maintain the width of the line wide enough to be fabricated with enough tolerance.