X/Ku dual-band single-layer reflectarray antenna

In this article, a single-layer dual-band reflectarray (RA) antenna is proposed. The RA antenna operates at two separated frequency bands with separate feeds. A low-profile dual-band unit cell I is designed with a 2 mm thickness without an air layer, which comprises only one dielectric substrate and two layers of metal patches. To achieve 360 degrees phase shift ranges at two bands, unit cell II is presented based on the phase delay line theory. On the basis of proposed unit cells, a single-layer circular RA (D = 150 mm) is designed, fabricated, and measured. The measured results show a measured peak gain of 20.7 dBi at 10.5 GHz and a 1 dB bandwidth of 17% (9.8-11.5 GHz). Besides, a measured peak gain of 23.6 dBi can be achieved at 15 GHz, and the 1 dB bandwidth is 13.3% (13.8-15.8 GHz) at Ku band.