A single layer reflectarray with octagonal-ring delay line for X-band applications

In this paper, a low cost broadband single layer reflectarray is proposed for X-band applications. The proposed reflectarray consists of truncated circular patch coupled to octagonalring delay line. The unit element is optimized to work at X-band with the center frequency of 10 GHz. A broad reflection phase range of more than 600° is obtained by varying the length of delay line. The reflectarray is designed on a low cost FR-4 substrate having size of 0.5λ
_o
. A 15 × 15 elements reflectarray with F/D = 1 is simulated to obtain the radiation characteristics. The design achieves 20 dB gain, low side-lobe-levels and broad phase range.