Two-Dimensional Scanning Array in Quad-Polarization Based on Pattern and Polarization Reconfigurable Element With Single Feed

In this communication, a phased array possessing 2-D scanning capability in quad-polarization (quad-Pol.) is proposed with larger element spacing. This array is based on a new pattern and polarization reconfigurable antenna, which is composed of four inverted-L antennas connected to the center probe through p-i-n diodes. By toggling the bias states of diodes, pattern reconstruction and polarization reconstruction (y-Pol., x-Pol., and ±45°-Pol.) can be achieved simultaneously, effectively improving the scanning and antijamming capabilities. Subsequently, a $6\times 6$ array with parasitic elements surrounding is designed and fabricated. The measured results demonstrated a scanning range of ±60° in the E- and D-planes for the y-Pol. and x-Pol. In the H-plane, the scanning range is within ±45°. For ±45°-Pol., a ±45° scanning range is implemented in the E- and H-planes. In the D-plane, benefitting from the pattern reconfigurability, a ±60° scanning range is covered. The maximum realized gains at 4.22 GHz are 19.23 and 19.56 dBi, respectively. The scanning gain fluctuation is within 3 dB. Compared with previous studies, the polarization diversity is introduced in 2-D scanning arrays to improve communication quality and antijamming ability. Meanwhile, the function realization is under the maximum element spacing of $0.54\lambda $ and single feed, saving 25% of the system cost.