Provided is an antenna unit, including a first substrate and a second substrate that are oppositely disposed, a liquid crystal layer located between the first substrate and the second substrate, and a third substrate located on a side of the second substrate away from the liquid crystal layer. The first substrate includes a first base substrate and a radiation unit layer. The second substrate includes a second base substrate and a ground layer. The radiation unit layer and the ground layer face the liquid crystal layer. The third substrate includes a third base substrate and a feed structure layer, wherein the feed structure layer is located on a side of the third base substrate away from the second substrate.