Dual-Polarized Linear Array With Overlapping Handover of Subarray to Produce Continuous Beam Scanning for Transmitarray Antenna

Focused aperture (FA) antenna with phase center of its feeder moving along the focal plane or focal arc is an effective and low-cost approach for beam scanning. Dual polarization is always desired in the communication system. In this article, a dual-polarized linear array with overlapping handover of subarray (OHSA) is proposed to produce continuous displacement of virtual point source on the basis of the Huygens equivalence principle. As the feeder of an FA antenna, the proposed OHSA not only enables continuous beam scanning electronically but also reduces the profile of the antenna. To validate the proposed scheme, a dual-polarized electronic beam-scanning transmitarray antenna with the profile of 3.46 lambda(0) is designed and measured. At the designed frequency 5.5 GHz, for both x- and y-polarizations, the measured gains are higher than 20.9 dBi, and the sidelobe levels (SLLs) are lower than -16 dB; within the bandwidth of 5.3 to 5.9 GHz and the scanning range of +/- 30 degrees, the gains are higher than 16 dBi, and the SLLs are lower than -8 dB. The isolation between dual-polarizations in the broadside radiation is higher than 29 dB. The back lobe is lower than -15 dB. The measured results are in reasonable agreement with the simulated ones.