An antenna apparatus includes antennas, each having first and second feeding portions facing each other across a dielectric layer, and third and fourth feeding portions facing each other across the dielectric layer, and a signal application unit configured to apply a wireless communication signal to the antennas, and including a plurality of output ports, wherein the first and second feeding portions are configured to receive electric signals having a first polarization characteristic, and are respectively connected to first and second output ports that are different from each other among the plurality of output ports, and the third and fourth feeding portions are configured to receive electric signals having a second polarization characteristic that is different from the first polarization characteristic, and are respectively connected to third and fourth output ports that are different from each other among the plurality of output ports.