Novel Reconfigurable Fractal Antenna Design based Metasurface Layer for Modem Wireless Systems

A novel wideband-pattern reconfigurable metasurface antenna based on H-tree fractal slots is presented in this work. the H-tree fractal slots patch illuminates a metasurface layer of $5\times 5$ unit cells array. Four PIN diodes are embedded in the patch, in the H-tree slots, to switch the radiating slots and control the antenna radiations. The individual unit cell dimensions are $33\times 33m\text{m}^{2}$. The overall antenna size is $173\times 173\times 56.6m\text{m}^{3}$. Switching the antenna by PIN diodes, the antenna main lobe can be steered toward different nine directions. The antenna provides again in the front lobe direction of 8. 99dBi at 1. 268GHz without significant change degradation in the gain during the beam steering process. Nevertheless, the antenna shows a wide operating frequency bandwidth of 55.5% from 0.978-1.73 GHz around the frequency resonance of interest. The proposed design shows a novelty in controlling the main lobe direction by switching four PIN diodes to be steered from −10° to 10°. The diode switching process shows no significant effects on the antenna bandwidth. The proposed antenna is designed with aid of a software package based on the finite integration technique of the CST MWS formulations.