An antenna is described including a slot formed in a cavity, a substrate configured to cover a portion of the cavity and the slot, and a first port and a second port configured to supply power to the antenna using a first feeding line and a second feeding line. Each of the feeding line and the second feeding line is connected to the slot in a vertical direction and disposed to be separate from one another. A first input impedance of the antenna from the first port differs from a second input impedance of the antenna from the second port.