Dual-Band Widebeam Dual-Polarized Antenna for Full-Duplex Communications

Abstract

This paper proposes an in-band full-duplex (IBFD) antenna with dual-band widebeam dual-polarized radiation. The antenna is composed of two orthogonal dual-band printed dipoles, i.e., one is with a single-ended feed for the transmitting (Tx) and the other is with a differential feed for the receiving (Rx). A high isolation among Tx and Rx ports is achieved by exploiting the symmetry of the design, which is maintained by modifying the feeding and structure of the printed dipoles. Two techniques of angled-dipole and cavity-backed reflector are employed to broaden the beamwidth in the lower and upper bands, respectively. A dual-band design operating at 2.45/5.8 GHz is characterized. A wideband out-of-phase power divider is employed to realize the differential-feed. The antenna achieves a 10-dB return loss bandwidth of 2.35 – 2.53 GHz and 5.64 – 6.02 GHz and Tx-to-Rx port isolation of ≥43 dB. Moreover, the full-wave simulator results in a cross-polarization level of ≤–30 dB, a realized gain of 6.0 dBi and 4.5 dBi, and a 3-dB beamwidth of broader than 88° and 120° at the lower and upper bands, respectively.