A multi-antenna includes a substrate, a first antenna element including two linear antennas extending in two different directions from a first feeding point, and a second antenna element including two linear antennas extending in two different directions f...

An antenna device includes circuitry configured to determine a first distance between a marker center and a fisheye lens, based on a first elevation angle and a coordinate of a marker along a third axis, determine second distances between the fisheye lens,...