  We analyze populations of Kuramoto oscillators with a particular distribution
of natural frequencies. Inspired by networks where there are two groups of
nodes with opposite behaviors, as for instance in power-grids where energy is
either generated or consumed at different locations, we assume that the
frequencies can take only two different values. Correlations between the value
of the frequency of a given node and its topological localization are
considered in both regular and random topologies. Synchronization is enhanced
when nodes are surrounded by nodes of the opposite frequency. We find
analytical estimations for the minimum value of the coupling strength between
oscillators that guarantees the achievement of a globally synchronized state,
getting a very good agreement with the numerical simulations.
