A Wideband Full-Duplex Dual-Polarized Antenna with Conical Radiation Pattern

This paper presents a wideband dual-polarized antenna with conical radiation pattern for use in in-band full-duplex (IBFD) communications. The design includes a horizontally polarized (HP) dipole array and a vertically polarized (VP) monopole antenna. The dipole array is excited by a feeding network with an in-phase 1:4 power divider to achieve omnidirectional radiation in the horizontal plane. Each HP element is fed by an out-of-phase power divider for improving polarization purity, and consequently, achieving a high isolation. The final design yields an overlapped impedance bandwidth of 48.08% (3.27 - 5.34 GHz), a port-to-port isolation of >40 dB, and satisfactory conical patterns in both modes. With the features of wideband, conical pattern, high isolation, the proposed antenna is a good candidate for indoor access point in the IBFD systems.