  In this paper an approach for broadening of operational band in a dense array
of dipole antennas by implementing passive split-loop resonators (SLRs) as
decouplers is presented. Compared to the previous method, where three closely
located active dipoles were decoupled by two passive dipole, the operational
band is significantly improved from $0.5 \%$ to $1.6 \%$ at the same level of
decoupling -8dB for the cross-talk and inter-channel transmittance. To
delineate, the presence of two SLRs results in birefringence of the resonant
interaction of SLRs which creates two different eigenmodes for decoupling. As a
result, a dual-resonant decoupled band is obtained. Alongside with analytical
investigation, numerical and experimental investigations verify the veracity of
our approach. Moreover, the possibility of decoupling by SLRs for arrays with
more active dipoles is investigated numerically.
