A Luneburg lens antenna device includes a Luneburg lens, a plurality of patch antennas, and a plurality of low-frequency antennas. The Luneburg lens is formed in a cylindrical shape and includes three dielectric layers having different dielectric constants and stacked on each other in the radial direction. The plurality of patch antennas respectively include ground electrodes which cover the outer peripheral surface of radiating elements, and form high-frequency MIMO antennas. The plurality of low-frequency antennas are monopole antennas using the ground electrodes, and form low-frequency MIMO antennas.