Two-Bit Planar Coding Reconfigurable Array Antenna for Dual-Polarized Wide-Angle Beam Scanning

In this communication, a dual-polarized coding reconfigurable array (coding RA) antenna with the characteristics of being low-profile, low-cost, relatively low-sidelobe, and wide-angle beam scanning is proposed. By exciting the array via different feeding ports, horizontal- and vertical-polarized scanning beams can be generated. By adjusting the p-i-n diodes integrated on the feeding lines, the element presents four different phase states of -270 degrees, -180 degrees, -90 degrees, and 0 degrees, labeled as "00," "01," "10," and "11." An eight elements array antenna is designed based on the element. With the introduction of elaborately designed two groups of fixed phase delay, the sidelobe level (SLL) at different scanning angles can be effectively reduced in two polarized directions and the gain is also improved. The simulated and measured results of the fabricated prototype indicate that dual-polarized +/- 60 degrees wide-angle beam scanning, moderate array gain, relatively low SLL, and low cross-polarization level can be achieved. The proposed array antenna, which according to the authors' best knowledge, is the first dual linear-polarized wide-angle beam scanning coding RA without the feeding horn, might have good applications in the base station and fully polarimetric radar.