Abstract: An antenna attachment including: a male screw part to be screwed with an antenna main body of an antenna device to be installed on a moving body, the male screw part including a head portion, a thread portion, and an intermediate portion between the head portion and the thread portion having a cross section smaller than the head portion and the thread portion; and a washer including a hole portion allowing passage of part of the male screw part. The hole portion has a shape in which a first hole and a second hole having different sizes are overlapped. The first hole has a shape not allowing passage of the head portion and the thread portion and allowing passage of the intermediate portion. The second hole has a shape not allowing passage of the head portion and allowing passage of the thread portion and the intermediate portion.

Abstract: An antenna device including: an antenna element; an enclosure having a wall body on which the antenna element is placed in a state of being joined to an inner surface of the wall body; and a printed substrate on which the antenna element is mounted with a leg portion of the antenna element connected to one surface of the printed substrate, which is stored inside the enclosure. Holding pieces to sandwich the antenna element between the wall body of the enclosure and the holding pieces are formed at a predetermined interval on the inner surface of the wall body of the enclosure. Respective sizes of and intervals between the holding pieces are set such that a difference between a deflection amount of the wall body and a deflection amount of the antenna element when the enclosure vibrates is less than or equal to a predetermined value.

Abstract: Disclosed is an antenna device that includes a capacitor element, a first coil, a second coil, and a capacitor. One end of the first coil is connected to a feeding point and another end of the first coil is connected to the capacitor element. One end of the second coil is connected to the capacitor element. One end of the capacitor is connected to the second coil and another end of the capacitor is connected to a grounding point.

Abstract: Disclosed is an antenna device that includes a capacitor element, a first coil, a second coil, and a capacitor. One end of the first coil is connected to a feeding point and another end of the first coil is connected to the capacitor element. One end of the second coil is connected to the capacitor element. One end of the capacitor is connected to the second coil and another end of the capacitor is connected to a grounding point.

Abstract: An antenna device mounted to an automobile includes an antenna component and an amplifier board provided with an amplifier to amplify signals received by the antenna component. The antenna component includes a metal plate and a resonance point adjusting coil having a first end connected to the metal plate, the resonance point adjusting coil being connected to an input terminal of the amplifier board at the first end via the metal plate. The impedance of the antenna component is adjustable by the mount angle of the resonance point adjusting coil to the antenna component.

Abstract: An antenna device mounted to an automobile includes an antenna component and an amplifier board provided with an amplifier to amplify signals received by the antenna component. The antenna component includes a metal plate and a resonance point adjusting coil having a first end connected to the metal plate, the resonance point adjusting coil being connected to an input terminal of the amplifier board at the first end via the metal plate. The impedance of the antenna component is adjustable by the mount angle of the resonance point adjusting coil to the antenna component.

Abstract: Provided is an antenna device having a reduced height and enhanced receiving sensitivity. The antenna device includes an antenna base and an antenna cover fixed to the antenna base. The antenna cover includes a resin cover body and a capacitive element integrally molded with the cover body and functioning as at least any one of a capacitance hat and an inductor. The antenna device 1 further includes a helical element electrically connected to the capacitive element and an antenna board electrically connected to the helical element and disposed on the antenna base.

Abstract: A load driver includes a switching element connected to a load, a constant current generator that generates a constant current, and a driver circuit that turns on the switching element for an on-period, which depends on a value of the constant current and is shortened with an increase in the value of the constant current. The constant current generator supplies a first constant current having a first current value to the driver circuit during the on-period, and supplies a second constant current having a second current value smaller than the first current value after the on-period has elapsed and the switching element reaches an on state.