A Mutual-Coupling-Suppressed Dual-Band Dual-Polarized Base Station Antenna Using Multiple Folded-Dipole Antenna

An interleaved shared-aperture dual-band dual-polarized base station array antenna is proposed in this article. The lower-band (LB) element realized by using a multiple folded-dipole (MFDA) and four parasitic loops. To interpret the working principle of MFDA, double (DFDA) firstly analyzed transmission line (TL) model. Then, combining two bended DFDAs introducing loops, low cross-band scattering LB with high out-of-band rejection level 16 dB obtained to cover 2.3–2.7 GHz. higher-band (HB) wide impedance bandwidth 42.5% (3.0–4.6 GHz), roll-off rate (RoR) 249.2 dB/GHz, 17 meander loop (MLL), rectangular (RL), V-shaped strips (VSS) near dipole arms. By low-scattering low-pass high- RoR high-pass HB element, novel small frequency ratio 1.46 isolation 25 realized. Due characteristic filtering response radiation patterns wideband sub-arrays are almost unaffected.