A Low-Profile Broadband Dual-Polarized Omnidirectional Antenna for LTE Applications

In this letter, a broadband dual-polarized antenna with a very low profile and omnidirectional gain patterns is designed for 1.7-2.7 GHz Long Term Evolution (LTE) mobile communications. The designed antenna is constituted by a miniaturized tapered monopole for vertical polarization (VP) and four planar dipoles arranged in a ring for horizontal polarization (HP). The HP antenna is used as the metal ground of the VP antenna, which can avoid the feeding intersection and solve the problem of impedance matching degradation when distance between the HP antenna and the metal ground of the VP antenna is close. By sharing the partial structure, the designed antenna achieves a compact size of 110 mm × 110 mm × 13 mm and an extremely low height of 0.07 λ min ( λ min is the free-space wavelength at the minimum operating frequency). The design achieves an overlapping bandwidth of 45% (1.7-2.7 GHz) with an isolation higher than 20 dB. High efficiency, low cross polarization and good omnidirectivity in the horizontal plane are obtained. The designed antenna is fabricated and measured, and it performs a great consistency between the simulation and measurement.