An antenna device includes a ground electrode, a feed element, and a parasitic element. The ground electrode has a substantially non-square rectangular plane shape that includes a first side extending in a first direction and a second side extending in a second direction orthogonal to the first direction. The feed element has a substantially rectangular plane shape and is formed in such a way that each side of the feed element becomes parallel to the first direction or the second direction. The parasitic element is formed in such a manner as to face a side of the feed element parallel to the first side. The feed element is configured to radiate a first polarized wave that excites in the first direction and a second polarized wave that excites in the second direction. The length of the first side is longer than the length of the second side.

An antenna is provided for operation across multiple frequency bands. The antenna includes, in order, a ground plane and a first conductive member separated from the ground plane. The antenna also includes a pair of second conductive members forming, with the first conductive member, a resonant structure sized to resonate at a higher frequency band of the multiple frequency bands. The antenna further includes a pair of third conductive members forming a resonant structure sized to resonate at a higher frequency band of the multiple frequency bands. The first conductive member is sized to resonate at a lower frequency band of the multiple frequency bands.

An antenna is provided for operation across multiple frequency bands. The antenna includes, in order, a ground plane and a first conductive member separated from the ground plane. The antenna also includes a pair of second conductive members forming, with the first conductive member, a resonant structure sized to resonate at a higher frequency band of the multiple frequency bands. The antenna further includes a pair of third conductive members forming a resonant structure sized to resonate at a higher frequency band of the multiple frequency bands. The first conductive member is sized to resonate at a lower frequency band of the multiple frequency bands.

A planar antenna device includes: a dielectric; an antenna layer provided on one main surface of the dielectric; and a ground layer provided on an other main surface of the dielectric to oppose the antenna layer. The planar antenna device generates an electric field in a first direction along the other main surface by radiating radio waves with linear polarization from the antenna layer. The ground layer includes a grid-like ground electrode portion and a plurality of openings positioned in regions other than the ground electrode portion, each of the plurality of openings being quadrilateral in shape. Each of the plurality of openings includes two first opening sides parallel to the first direction and two second opening sides perpendicular to the first direction. A length of each of the first opening sides is longer than a length of each of the second opening sides.

A planar antenna device includes: a dielectric; an antenna layer provided on one main surface of the dielectric; and a ground layer provided on an other main surface of the dielectric to oppose the antenna layer. The planar antenna device generates an electric field in a first direction along the other main surface by radiating radio waves with linear polarization from the antenna layer. The ground layer includes a grid-like ground electrode portion and a plurality of openings positioned in regions other than the ground electrode portion, each of the plurality of openings being quadrilateral in shape. Each of the plurality of openings includes two first opening sides parallel to the first direction and two second opening sides perpendicular to the first direction. A length of each of the first opening sides is longer than a length of each of the second opening sides.

An electronic device may include a housing including a first cover, a second cover, and a slot positioned in a first side surface. A first antenna is positioned between a first inner surface and a second inner surface, facing the slot, and configured to operate in a first frequency band, and a second antenna is positioned between the first inner surface and the second inner surface, facing the first antenna, and configured to operate in a second frequency band different from the first frequency band.

An electronic device may include a housing including a first cover, a second cover, and a slot positioned in a first side surface. A first antenna is positioned between a first inner surface and a second inner surface, facing the slot, and configured to operate in a first frequency band, and a second antenna is positioned between the first inner surface and the second inner surface, facing the first antenna, and configured to operate in a second frequency band different from the first frequency band.

An antenna module (10) includes a ground electrode (30) in which a slit (33) is formed in such a manner as to form an opening along a perimeter of the ground electrode, a first antenna (110) and a second antenna (110A) arranged in or on the ground electrode (30), and a coupling reducing electrode (200) connected to the ground electrode (30) within the slit (33). The slit (33) is formed on a path leading from the first antenna (110) to the second antenna (110A) along the perimeter of the ground electrode. The coupling reducing electrode (200) includes a first conductor (220) having a length corresponding to a first frequency and a second conductor (230) having a length corresponding to a second frequency, which is higher than the first frequency.

An antenna module (10) includes a ground electrode (30) in which a slit (33) is formed in such a manner as to form an opening along a perimeter of the ground electrode, a first antenna (110) and a second antenna (110A) arranged in or on the ground electrode (30), and a coupling reducing electrode (200) connected to the ground electrode (30) within the slit (33). The slit (33) is formed on a path leading from the first antenna (110) to the second antenna (110A) along the perimeter of the ground electrode. The coupling reducing electrode (200) includes a first conductor (220) having a length corresponding to a first frequency and a second conductor (230) having a length corresponding to a second frequency, which is higher than the first frequency.

An antenna system includes a dielectric substrate, a ground element, and a first antenna element. The dielectric substrate has a first surface and a second surface, which are opposite to each other. The ground element is disposed on the first surface of the dielectric substrate. The first antenna element includes a first radiation element, a feeding radiation element, a second radiation element, and a shorting radiation element. The first radiation element has a feeding point, and is disposed on the second surface of the dielectric substrate. The feeding radiation element is adjacent to the first radiation element. The second radiation element is coupled to the feeding radiation element. The second radiation element is further coupled through the shorting radiation element to the ground element.