A Sub-Wavelength Reflectarray Element Based on Minkowski Fractal Loop

A novel reflectarray element consists of one Minkowski fractal loop in combination of a square loop is proposed. The size of the element is two fifth of a wavelength of the working frequency of 5.8 GHz. The proposed element offers a slope value of 20°/mm, while the phase range is in excess of 411°. Utilizing the proposed element, a $10\times 10$ reflectarray antenna is simulated. Simulation results show that the antenna gain is 18.9 dBi at its working frequency 5.8 GHz, and has an impedance bandwidth $(\vert S_{11}\vert of 3 % $(5.73\sim 5.9 \mathrm{GHz})$ .