High-Isolated Full-Duplex Dongle Antenna Based on Even-Mode Suppression for B5G Communications

Abstract

A space-shared full-duplex antenna with high isolation is proposed for universal serial bus (USB) dongles. A compact antenna with a compact size of 22 mm x 4 mm comprises a loop and dipole antennas, working as a vertical monopole and a horizontal dipole, respectively. The dipole-type is fed by a microstrip-slotline transition with filtering characteristics of odd-mode bandpass and even-mode bandstop, avoiding the even-mode excitation for the loop antenna. The inherent isolation is caused by the orthogonality of the modes and the even-mode suppression (caused by the microstrip-slotline transition). Thus, high port isolation, low envelope correlation coefficients (ECC), and high efficiency are achieved across the 5G band of 3.4-3.6 GHz.