Differential and Symmetrical Decoupling Network for Differentially Fed Antennas

This letter proposes the differential and symmetrical decoupling network (DSDN), a novel method specifically designed to decouple differentially fed antennas (DFAs) while preserving their structural symmetry. DFAs offer several advantages over single-fed antennas (SFAs) due to their symmetrical design, but the presence of multiple antenna ports and coupling paths poses challenges for decoupling. Existing methods for SFAs disrupt the structural symmetry of DFAs. The DSDN significantly enhances the isolation between DFAs, and its effectiveness is validated through theoretical derivations, simulations, and experimental measurements on a 1 × 2 DFA array and a 1 × 4 DFA array. The results demonstrate isolation improvements of 53 and 40 dB at the center frequency for the 1 × 2 and the 1 × 4 DFA array, respectively, compared with the coupled array. The DSDN offers a promising solution for decoupling DFAs, allowing for significantly improved performance while maintaining structural symmetry.