Wireless repeaters comprising antennae having high electrical isolation are presented. Multi-band antennae are placed on opposing sides of a conductive ground plane to achieve high electrical isolation, preferably higher than 30 dB. The antennae are preferably placed at a distanced from the ground plane that is less than 0.5 wavelengths of a frequency associated with frequency bands to which the antennae are responsive. The presented antennae system reduces the minimum amount of isolation required for stable operation.