Multiband High-Gain Printed Yagi Array Using Square Spiral Ring Metamaterial Structures for S-Band Applications

This letter presents the design, implementation, and measured results of a novel multiband square spiral ring (SSR) metamaterial-embedded printed Yagi antenna array for WiFi, Bluetooth, WLAN, and WiMAX applications. High gain is achieved in the S-band, at four distinct frequencies. It is achieved as a result of simultaneous excitations of segments of the SSR metamaterial, coupling from dipole elements, and by arranging the proposed Yagi antenna in an array of two elements using a Wilkinson power divider. Parametric analysis of unit-cell SSR metamaterial is done in CST, and controlling of frequency resonances in the desired bands is achieved by tuning specific SSR metamaterial geometrical parameters. Proposed antennas are fabricated, and the measured gain and S11 response results are presented and compared to the simulated results for demonstrating performance of the proposed Yagi antennas and accuracy of the simulated results.