A Symmetrical Decoupling Method for Differentially-Fed Antennas (DFA)

In this paper, we introduce a novel decoupling technique designed specifically for differentially-fed antennas (DFAs). DFAs offer several advantages over single-fed antennas (SFAs), including inherent low cross-polarization and heightened resilience to environmental disturbances. These benefits arise from the symmetrical structure and differential feeding mode of DFAs. However, mitigating coupling issues in DFAs presents a more formidable challenge compared to SFAs, primarily due to the presence of multiple ports and complex coupling pathways. The key distinction of our proposed method, known as differential and symmetrical decoupling network (DSDN), lies in its ability to maintain the overall antenna structure's symmetry. This preservation ensures that the unique advantages associated with differential feeding remain intact. To validate the feasibility of our approach, we conduct simulations, fabrication, and measurements on a 1×2 DFA array. The results demonstrate a significant improvement in isolation, with a 53 dB enhancement at the center frequency of 2.45 GHz.