Backwards compatibility for MIMO systems based on IEEE 802.11a

An improved liner for a shaped explosive charge has a metal side wall with an outer side surface which is adapted to be engaged by the explosive charge and an inner side surface which defines an outwardly flaring cavity. The side wall is formed of a single crystal of metal and is free of grain boundaries. The single crystal of metal is composed of atoms arranged as unit cells all having the same orientation relative to the central axis of the cavity. This tends to optimize the performance of the shaped charge and allows the designer of the shaped charged freedom to completely specify the crystallographic orientation of the side wall of the liner.