Embodiment high-frequency radiator includes two plus and minus 45-degree single-polarized radiators. The single-polarized radiator includes a radiation arm, a balun, a feeder circuit, a filter, and a ground plane. The radiation arm and the balun are electrically connected. The feeder circuit and the balun are separately disposed on two surfaces of a first dielectric plate that is placed vertically. The ground plane is disposed on a downward surface of a second dielectric plate that is placed horizontally. The first dielectric plate is vertically disposed on the second dielectric plate, and the filter includes a capacitor branch and an inductor branch. The inductor branch is disposed on a same surface of the first dielectric plate as the balun, the inductor branch is separately electrically connected to the balun and the ground plane, and the capacitor branch is coupled to the ground plane.