The antenna includes a first antenna unit and a second antenna unit. The first antenna unit and the second antenna unit are disposed on the same surface of a substrate. The first antenna unit includes a first primary radiation unit and a first secondary radiation unit, and the second antenna unit includes a second primary radiation unit and a second secondary radiation unit. A gap exists between the first primary radiation unit and the second primary radiation unit. The first secondary radiation unit is connected to one end of the first primary radiation unit that is away from the second primary radiation unit, the second secondary radiation unit is connected to one end of the second primary radiation unit that is away from the first primary radiation unit, and the first secondary radiation unit and the second secondary radiation unit are located on the same side of the substrate.