ANTENNA APPARATUS

An antenna apparatus includes a first ground plane; a second ground plane having first, second, third and fourth sides, a cutout part, and a slit having an open end; a first radiating element having first and second lines, and a feeding point; a second radiating element having a third line; and a parasitic element having first and second parasitic lines. A length from the feeding point to an end part of the slit is set to one-half wavelength at a first communication frequency, a total length of a length from an end part of the fourth line to the feeding point, and a length from a ground potential point to an end part of the second parasitic line is set to one-half wavelength at a second communication frequency, and a length of the third line and the fourth line is set to one-quarter wavelength at a third communication frequency.