Abstract: This invention is in the field of base station antennas for wireless communications. The present invention refers to a slim multi-band antenna array for cellular base stations, which provides a reduced width of the base station antenna and minimizes the environmental and visual impact of a network of cellular base station antennas, in particular in mobile telephony and wireless service networks. A multiband antenna array comprises a first set of radiating elements operating at a first frequency band and a second set of radiating elements operating at a second frequency band, said radiating elements being smaller than ?/2 or smaller than ?/3, being (?) the longest operating wavelength. The ratio between the largest and the smaller of said frequency bands is smaller than 2.