Compact reflectarray antenna element using split ring resonator

This paper presents a compact reflectarray element using split ring resonators (SRRs) for small size and high gain reflectarray design. The proposed element is constructed of dual concentric split rings and a metal line on different layers. Several design parameters of the unit cell are studied for obtaining better phase response. The proposed unit cell achieves a good phase response of 700 degrees at X-band. The unit cell size is 14 mm × 14 mm (0.36 λ₀ × 0.36 λ₀). Due to the small unit cell size, the reflectarray with the proposed element can be expected to achieve high gain.