A Dual Polarized Shared Aperture Compact Unit Cell Element for Antenna Array Applications

A dual polarized compact unit cell antenna element is presented for shared aperture antenna arrays. The unit cell is composed of two linearly polarized antennas sharing the same aperture both operating at the same frequency band. The unit element has about % 7.06 bandwidth (VSWR<1.22) and the isolation between each antenna in the unit cell is more than -43 dB. The unit cell element has cross polarization level better than -40 dB in the principle plane. The unit cell is composed of full metal to have only metallic losses. The proposed unit cell spacing is about 0.885λ
0
at the center frequency to prevent grating lobes in the band. The proposed unit cell structure allows compact construction of the feed network for array antenna applications.