Low-Profile Dual-Polarized Omnidirectional Antenna With Enhanced Isolation for Full-Duplex Applications

A low-profile, dual-polarized omnidirectional (DPO) antenna with enhanced isolation is presented for in-band full-duplex applications. The proposed design integrates two orthogonally polarized antennas in a stacked configuration. By strategically amalgamating coupling enhancement and reduction concepts, an effective balance between low profile and favorable performances is achieved. Meanwhile, a novel decoupling technique is developed, wherein coupled shorting probes are introduced to shunt unwanted coupling currents away from Rx port, significantly enhancing the isolation. Measurement results validate the proposed approach. The prototype with a low profile of 0.1 λmin, exhibits overlapped impedance bandwidth of 17.5% (2.3–2.75 GHz). Within this band, an enhanced isolation of over 39 dB (peak isolation of 64 dB at 2.6 GHz) and stable doughnut-shaped radiation patterns for Tx and Rx antenna are also attained.