1-Bit reconfigurable reflectarray antenna with T-shaped parasitic structure

In this paper, an electronically 1-bit reconfigurable reflectarray antenna (RRA) with wide-angle beam-scanning and high efficiency performance is presented for formation satellite communication applications. A 1-bit phase distribution can be generated by controlling the state of the PIN dipole in the configurable element comprising a double split ring (DSR) patch and two T-shaped parasitic structures. The resonant frequency of the DSR patch in both states can be optimised by a T-shaped parasitic structure, which is beneficial to improving the bandwidth and aperture efficiency. A 180 degrees +/- 20 degrees phase difference can be realised from 9.7 to 10.3 GHz only by controlling one PIN dipole loaded on the proposed element, which ensures stable radiation performance over a larger band. To validate the effectiveness of the proposed element, a prototype RRA containing 20 x 20 units is designed and measured. A +/- 60 degrees beam scanning range with the gain drop of 3.2 and 3.3 dB in the xoz and yoz planes is realised, which verifies the wide-angle beam-scanning ability of the RRA. The measured peak gain is 25 dBi at 10 GHz in the broadside direction, corresponding to an aperture efficiency of 25.2%. Meanwhile, the 1-dB gain bandwidth of the proposed RRA is 12.6%.