Abstract: An antenna device includes: a conductive ground conductor plate; a plate-shaped radiating element disposed without being in contact with the ground conductor plate; a feeding line including a conductor and a shield member that surrounds the conductor, the shield member being connected to the ground conductor plate; and a conductive feeding element that includes a facing plate portion that faces the radiating element with an air layer provided therebetween, and is connected to the conductor.

Abstract: An onboard antenna module includes: a plate-shaped member that is fixed to a body of a vehicle and at least a portion of which is plate-shaped; and a plurality of antennas that are provided on the plate-shaped member, wherein a plurality of antennas included in the plurality of antennas provided on the plate-shaped member constitute a first diversity antenna configured to receive RF (Radio Frequency) signals in a first frequency band, and at least two antennas included in the plurality of antennas that constitute the first diversity antenna are respectively provided in two regions that are not adjacent to each other when a flat surface of the plate-shaped member is divided into quadrants around a center point of the flat surface.

Abstract: An antenna device includes a ground plate, a patch section parallel to, and spaced apart from, the ground plate, a first short circuit section having a plurality of first conductive elements that electrically connect the patch section and the ground plate, and a second short circuit section having a plurality of second conductive elements electrically connected at one end to the ground plate. The plurality of first conductive elements are arranged in a circle with a first radius from a patch center point and provide a preset inductance. The plurality of second conductive elements are arranged in a circle with a second radius from the patch center point and provide a preset inductance.

Abstract: An antenna device includes a ground plate, a patch section parallel to, and spaced apart from, the ground plate, a first short circuit section having a plurality of first conductive elements that electrically connect the patch section and the ground plate, and a second short circuit section having a plurality of second conductive elements electrically connected at one end to the ground plate. The plurality of first conductive elements are arranged in a circle with a first radius from a patch center point and provide a preset inductance. The plurality of second conductive elements are arranged in a circle with a second radius from the patch center point and provide a preset inductance.