Radiating unit and base station antenna

The invention relates to a radiation unit and a base station antenna. The radiation unit comprises a dielectric substrate and a metal circuit. The metal circuit comprises a radiation part, a balun part, a lightning protection part and a feed part; the radiation part is arranged on the surface of one side, deviating from the bottom plate part, of the top plate part, and penetrates through the top plate part to extend to the Balun part; the balun part is arranged on the inner side surface or the outer side surface of the supporting part; the lightning protection part is arranged on the surface of one side, facing the top plate part, of the bottom plate part and penetrates through the bottom plate part to be grounded; the feed part is arranged on the surface of the side, away from the top plate part, of the bottom plate part and connected with the balun part. Wherein the thickness H of the radiation part along the extension direction of the support part meets the condition that H is less than 0.05 lambda, the ap