Low-Profile Dual-Polarized Composite Patch-Monopole Antenna With Broadband and Widebeam Characteristics

This paper presents a low-profile, high-isolation, dual-polarized antenna with broadband and widebeam characteristics. The antenna consists of a square patch fed by double differential-fed scheme for the high-isolation dual-polarized radiation. The patch is loaded with four top-hat monopoles to not only broaden the beamwidth, but also generate an extra resonance, which is utilized to improve the operational bandwidth. For verification, an antenna prototype with
$0.096\lambda _{0}$
-height at the center frequency of 2.5 GHz has been fabricated and measured. The measurements result in a 10-dB return loss bandwidth of 13.8% (2.36 - 2.71 GHz), an isolation of ≥ 43 dB, and excellent widebeam dual-polarized radiation, i.e., at 2.4 - 2.6 GHz, its half-power beamwidths are ≥ 180° and ≥ 120° in the E- and H-planes, respectively.