A Broadband Dual-Polarized Dipole Filtering Antenna Based on Parasitic Structure

A wideband dual-polarized loop dipole antenna that can function in the 5G frequency band's Sub-6GHz is proposed in this paper. The two radiation nulls produced in this paper are primarily produced by electromagnetic cross-coupling technology. Loading the leaf-shaped structure on the loop dipole arm introduces higher frequency radiation zeros. Below the loop dipole arm, the parasitic ring loading can produce radiation zeros at a lower frequency. The filtering dipole antenna's quality of stopband suppression is increased by the loading of the parasitic ring and leaf-shaped structure. A square parasitic structure is loaded above the dipole arm to create a new resonance mode and increase the dipole antenna's impedance matching bandwidth. According to simulation results, the antenna has a wide 65.4% impedance bandwidth (|S<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</inf>| is less than -10 dB between 2.77 and 5.46 GHz). The 1.5-2.15 GHz and 6–7 GHz frequency bands, respectively, have excellent out-of-band rejection levels of 23.2 dB and 20.6 dB, and the antenna's port-to-port isolation reaches 31 dB.