Low-frequency filtering unit having pattern with high consistency and antenna array

A low-frequency filtering unit comprising four vibrator arms, a balun base, a balun feeder line and a plurality of balun chamber tubes for arranging the balun feeder line, wherein each vibrator arm further comprises two radiation arms, and the two radiation arms further comprise a transverse radiation arm extending transversally and a longitudinal radiation arm extending longitudinally, wherein one end of the transverse radiation arm is vertically connected to one end of the longitudinal radiation arm to form an integral L-shaped right-angle structure, wherein each balun chamber tube is arranged at the connection between the transverse radiation arm and the longitudinal radiation arm, wherein the transverse radiation arm and the longitudinal radiation arm are provided with a wave-trap structure respectively, wherein the wave-trap structures on the transverse radiation arm and the longitudinal radiation arm are symmetrically arranged with a 45° angular bisector of the L-shaped right-angle structure as a center line;

• wherein the four vibrator arms are symmetrically arranged in pairs around the periphery of the balun base along a diagonal line and form an integral cross orthogonal structure, and wherein the four vibrator arms, the balun chamber tubes, the balun feeder line and the balun base are all made of metal conductors.