Antenna and fabricating method thereof, and antenna device and fabricating method thereof

An antenna, comprising:

• a first substrate;
• a base material layer on the first substrate and having a plurality of antenna cavities arranged in an array therein;
• and
• a conductive layer on a sidewall of each of the plurality of antenna cavities, each of the plurality of antenna cavities and the conductive layer on the sidewall thereof forming an antenna unit, wherein
• each of the plurality of antenna cavities comprises a first opening, and an aperture of the first opening at a position of the antenna cavity close to the first substrate is smaller than an aperture of the first opening at a position of the antenna cavity away from the first substrate, wherein
• each of the plurality of antenna cavities comprises a first cavity and a second cavity in physical contact with the first cavity, the second cavity being closer to the first substrate than the first cavity;
• the first cavity comprises a second opening, and the second cavity comprises a third opening;
• in a direction pointing from the second cavity to the first cavity, an aperture of the second opening gradually increases, and an aperture of the third opening is constant;
• and
• a difference between the aperture of the second opening at a position of the first cavity in physical contact with the second cavity and the aperture of the third opening is smaller than a first value.