An independent continuously scannable dual-beam liquid crystal phased array antenna for Ku-band

An independent continuously scannable dual-beam liquid crystal (LC) phased array antenna (DBLCPA) operating in the Ku-band is proposed for the first time in this article. Eight right-hand circularly polarised microstrip patch antennas (RHCPMPAs), four 90° hybrid couplers, eight liquid crystal phase shifters (LCPSs), and two power dividers form the proposed array antenna, which utilises the dynamic phase difference between LCPSs and the inherent phase difference of the 90° hybrid coupler to achieve scannable dual-beam driving. The proposed DBLCPA can be conceptualised as two one-dimensional phased array systems. By adjusting the phase difference of each group of LCPSs respectively, the two independent scannable beams can be achieved simultaneously. The S-parameters and far-field pattern of the fabricated antenna array are measured and analysed. The measured S11 and S22 of the DBLCPA is below −10 dB and the isolation is better than 10 dB at 11.5–12.5 GHz. The two beams can achieve independent continuous scanning in E-plane, in which the left beam is scannable between 0° and 40°, and the right beam is scannable among 0° to −40°. The measured maximum dual-beam gain of the antenna array is 11.3 dBi, while the axial ratio is less than 3 dB.