A wideband planar reflectarray antenna using clip-shaped elements for X-band applications

A single-layer wideband reflectarray antenna using clip-shaped elements for X-band applications is proposed. A linear phase shift of 398 degrees can be achieved by adjusting the longitudinal length of the interior folded slot of each element, while the exterior dimensions of each element remain identical. In this layout, a prolonged current path for an increased phase swing can be obtained and the sudden size variation between adjacent elements in the array can be avoided. A reflectarray antenna that is offset-fed and composed of 529 elements is modeled, manufactured, and tested, with a 0.3 lambda unit cell periodicity at the design frequency of 10 GHz. Experimental results exhibit that for 1-dB gain drop, a broad 41.0% bandwidth is obtained. The tested gain is 25.7 dBi at 10 GHz, which corresponds to aperture efficiency 68.5%. Additionally, stable and good radiation characteristics are also achieved.