  Stable propagation of large, multifilament arrays over long distances in air
paves new ways for microwave-radiation manipulation. Although, the dynamics of
a single or a few filaments was discussed in some of the previous studies, we
show that the stability of large plasma filament arrays is significantly more
complicated and is constrained by several trade-offs. Here, we analyze the
stability properties of rectangular arrays as a function of four parameters:
relative phase of the generating beams, number of filaments, separation between
them, and initial power. We find that arrays with alternating phase of
filaments are more stable than similar arrays with all beams in phase.
Additionally, we show that increasing the size of an array increases its
stability, and that a proper choice of the beam separation and the initial
power has to be made in order to obtain a dense and regular array of filaments.
