A Metamaterial-Based Circularly Polarized Antenna and Its Phased Array Application

this paper, a millimeter waves (mmW) metamaterial-based circularly polarized antenna and its 1x4 phased array is proposed. Excited by a triple crossed slot, a slotted patch can act as a metamaterial- based radiator. The feeding line beneath the coupling slot were designed as a notched ring. By adjusting the length of three coupling slots and the angle of notch, the proposed antenna can generate circularly polarized radiation. Single antenna element operating at 43GHz shows an impedance bandwidth operating from 39.3 to 47.7 (19.5%) and an axial ratio (ARs) bandwidth from 39.5 to 48.2 (20.2%). Then an 1x4 phase array based on the proposed antenna element is designed, which exhibits a combine bandwidth of 13.75% and the scanning range at 40GHz reaches +/- 30 degrees, thus making the proposed CP array a promising candidate for mmW applications.