On the Design of Dual-Polarised Linear Antenna Arrays with Enhanced Port-to-Port Isolation

Abstract

The paper describes the process of designing a dual-polarised linear antenna array with enhanced port-to-port isolation, with the example of a four-element array with isolation better than 60 dB for the U-NII 5.15–5.925 GHz band. As a single antenna, dual-polarised electromagnetically coupled microstrip antennas were used with port-to-port isolation not exceeding 25 dB. A significant improvement in the isolation of the array was achieved thanks to the application of a dedicated feeding network. On the basis of theoretical analysis, a mathematical model describing port-to-port isolation was developed. Circuit and full-wave simulations were carried out to show the influence of electromagnetic couplings between antennas and/or the microstrip lines of the feeding network and the selection of phase shifters/power dividers on the isolation. The fabricated prototype is characterised by a gain of about 14 dBi, polarisation purity of at least −27 dB within the main lobe and close to expectations isolation better than 57 dB within the whole operational band.

Design, Challenges and Developments for 5G Massive MIMO Antenna Systems at Sub 6-GHz Band: A Review

“…Circuit and full-wave simulations were performed to show the effect of electromagnetic coupling between the antennas and/or microstrip lines in the feed network and the effect of the phase shifter/power divider selection on isolation. The manufactured prototype featured a gain of approximately 14 dBi, a minimum polarization purity of −27 dB within the main lobe, and was close to the expected isolation of >57 dB over the entire operating range [ 111 ].…”

Millimeter-Wave Smart Antenna Solutions for URLLC in Industry 4.0 and Beyond

“…Polarization is also affected by mutual coupling. As the scan angle increases, the mutual coupling causes cross-polarization isolation to deteriorate [ 151 ]. To maintain polarization purity, polarization compensation techniques are sometimes used, which increase the cost and complexity of mmWave array design [ 152 , 153 , 154 , 155 ].…”