A support piece comprises: a first support section configured in the shape of a plate, and a plurality of second support sections; every second support section in the plurality of second support sections is set on the outside of the first support section and is bent relative to the first support section; every second support section comprises at least one support structure. At least a portion of the support structure of the at least one support structure is configured to support a first dipole arm, and at least a portion of the support structure of the at least one support structure is configured to support a second dipole arm; a second arm section on the outside of the first dipole arm is bent relative to the first arm section on the inside toward a first side of the first support section to support the dipole arm; a second arm section on the outside of the second dipole arm is bent relative to the first arm section on the inside toward a second side of the first support section opposite to the first side.