Dual-Band Base Station Antenna Array Using the Low-Band Antenna as Parasitic Decoupler

In this letter, a dual-band interleaved base station antenna array with self-decoupling characteristic is studied. The low-band antenna radiator along with its feeding baluns can be considered as compensation and partition structures for the high-band (HB) antennas. The measured co- and cross-polarized in-band isolations between the HB subarrays are enhanced to > 24.6 dB and > 29.3 dB, respectively, without introducing extra decoupling layer. The HB radiation performances are recovered, exhibiting good capability of crossband scattering suppression. The decoupling principles are analyzed and explained.