Design and Analysis of Single Layer Ku/K Band Integrated Element Reflectarray Antenna

A linearly polarized dual band reflectarray (RA) antenna designed, fabricated, and tested to operate in the Ku and K band frequencies is reported in this paper. The 24 x 24 cm(2) size RA is developed using 1058 integrated elements etched over a 0.275 mm thick Rogers RT5870 substrate. The integrated elements include concentric circular rings distributed co-centric with the source and the Malta cross elements distributed offset from the source. The distribution of these elements is done based on the 590 and 360 degrees phase change observed at 14.25 (Ku) and 22.5 (K) GHz by varying the size of the circular rings and the Malta cross respectively. The designed RA offers a simulated gain of 28.62 dBi at 14.25 GHz and 26.92 dBi at 22.5 GHz. These results are validated experimentally using the fabricated prototype. A measured peak gain of 28 and 26.4 dBi are observed with sidelobe levels (SLL) of -21 and -11 dB at 14.25 and 22.5 GHz respectively. The cross-polarization levels measured at the resonant frequencies are <-31 and <-28 dB. The proposed dual-band RA covers the entire Ku band uplink frequencies utilized for fixed satellite services and the K band downlink frequencies useful for earth exploration satellite services.