Reducing the width of planar Yagi-Uda antennas using square-shaped split ring resonators (SRRs)

A novel planar Yagi-Uda antenna is proposed in this work. The canonical dipole resonators constituting the driven, reflector and director elements are replaced here with square-shaped split-ring resonators (SRRs). This solution allows for a reduction of the width of the antenna roughly by a factor of two, while maintaining good radiation performance. As a proof of concept, a 5-elements prototype working within the WLAN frequency band is designed and fabricated. The measurements exhibit reasonably good agreement with simulations, and highlight the validity of the proposed approach for obtaining compact Yagi-Uda arrays in planar geometry.