Antenna element used for multi-band antenna dual polarization

An antenna element used for multi-band antenna dual polarization, comprising:

• four radiating elements, a balun element configured to feed power to the radiating elements, and a fastening plate configured to fasten the balun element, wherein
• the balun element comprises two dielectric plates, the two dielectric plates being embedded into each other in a crossing manner, two signal transmission units, one feeding unit, and two filtering units printed on each dielectric plate (203), the filtering units being used for decoupling;
• and, wherein
• each of the filtering units comprises one or more filtering modules, wherein the one or more filtering modules are connected in parallel or in series, wherein
• a given one of the one or more filtering modules comprises a first metal piece and a second metal piece, wherein
• the first metal piece is printed on the second surface of the dielectric plate, and the first metal piece at least partially overlaps the signal transmission unit in space;
• and
• the second metal piece is disposed at a top end and/or a bottom end of the first metal piece, the second metal piece and the first metal piece are welded to each other, and the second metal piece does not overlap the signal transmission unit in space;
• and
• the two signal transmission units are disposed on a first surface of each dielectric plate, wherein top ends of the four signal transmission units are electrically connected to bottom ends of the four radiating elements respectively, the feeding unit being disposed on a second surface that is of each dielectric plate and that is opposite to the first surface, and a bottom end of the feeding unit and bottom ends of the signal transmission units are electrically connected to the fastening plate separately.