The invention provides an arrangement for use in an
antenna array for transmitting and receiving at at least one frequency in at least two polarizations, comprising at least two antenna elements (210-208), where each
antenna element is intended for one of the two polarizations, the antenna elements being arranged on a feeding structure (100, 320, 420) which conducts electrical signals to and from the antenna elements (201-208). The invention is characterized in that the feeding structure (100, 320, 420) comprises a number of waveguides (101) dimensioned for the said at least one frequency, in that the different waveguides are used for feeding the antenna elements (201-208) intended for different polarization, and in that the waveguides (101) are completely or partially filled with a material, the
dielectric constant of which is higher than that of air, whereby an
antenna array with small or negligible
grating lobes can be obtained.The antenna elements (201-208) and the feeding structure (100, 320) are suitably arranged each on a separate plate (200, 310, 410) and in the feeding plate (100, 320, 420), a number of continuous recesses (101) are arranged which are constructed to operate as waveguides at the said at least one frequency.