Patent attributes
A directional antenna includes a substrate, a power-supply radiating element, paired non-power-supply radiating elements, and a metal plate. The power-supply radiating element is formed on the front surface of the substrate to be along the vertical direction. The power-supply radiating element receives electric power from the power-supplying portion. The paired non-power-supply radiating elements are provided along the vertical direction and oppose each other across the power-supply radiating element in a horizontal direction which is a direction along the front surface of the substrate on the horizontal plane, when viewed in a front-rear direction. A part of the metal plate is provided behind a part of the power-supply radiating element. The metal plate is not provided behind the paired non-power-supply radiating elements. The 3 dB beam width of the directional antenna on the horizontal plane is equal to or greater than 180 degrees including the range forward of the directional antenna.