Embodiments of this application disclose an antenna apparatus, applied to the communications field. Embodiments of this application include: A feed converts a guided electromagnetic wave into a beam, and then sends the beam to a defocusing apparatus. Then, the defocusing apparatus may change a transmission direction of the beam. In this way, the defocusing apparatus sends the beam whose transmission direction is changed to a beam shaping panel, and the beam shaping panel changes the transmission direction of the beam and a transmission shape of the beam, and then transmits the beam to a peer antenna, to implement information transmission. The defocusing apparatus changes the transmission direction of the beam, so that a spatial distance between feeds may be increased, feed arrangement density may be reduced, and a case in which physical positions of the feeds overlap may be avoided, to properly arrange the feeds and ensure a communication effect.