Abstract: An antenna according to an aspect includes an antenna body configured to radiate an electromagnetic wave when entering a first mode exhibiting an artificial magnetic conductor character with respect to an electromagnetic wave in a first frequency band and entering a second mode serving as a resonator for the electromagnetic wave in a second frequency band higher than the first frequency band and a package receiving box (case) configured to support the antenna body and to be placed on a placement surface directly or via a placement member. The antenna body is supported by the package receiving box with a direction of an electrical current in the first mode being parallel to the placement surface.

Abstract: An antenna includes an antenna body and a housing case. The antenna body configured to enter a first mode exhibiting an artificial magnetic conductor character with respect to an electromagnetic wave in a first frequency band and configured to enter in a second mode (TM mode) serving as a resonator for the electromagnetic wave in a second frequency band higher than the first frequency band. The housing case includes a bottom plate on which the antenna body is installed and a side wall provided standing from the bottom plate and spaced with a distance from a periphery of the antenna body. The housing case is a case made of metal including an opening in a face through which the electromagnetic wave enters and exits.