An antenna device includes a plurality of antenna elements, each of the plurality of antenna elements including a radiating element and at least one parasitic element. The plurality of antenna elements are arranged in a direction intersecting with an arrangement direction of the radiating element and the at least one parasitic element of at least one antenna element of the plurality of antenna elements.
H01Q 19/28 - Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using a secondary device in the form of two or more substantially straight conductive elements
Provided is an on-vehicle antenna device able to prevent reduction in antenna gain from unnecessary resonance between a metal base and a vehicle body. Two conductor plates 90 are attached by eight screws 103 to a surface (lower surface) of a flat plate 71 on a resin base 70, said surface being on the opposite side from a surface (upper surface) with a metal base 60 disposed thereon. The screws 103 attach the conductor plates 90 to the lower surface of the resin base 70, and also attach the metal base 60 to the upper surface of the resin base 70. The metal base 60 and the conductor plates 90 are electrically connected by the screws 103. Each conductor plate 90 has four plate springs 92 that extend from a flat plate 91 towards the vehicle body side with downward diagonal curvature. The tip of each plate spring 92 approaches the electricity supply tube 62, and is in contact with the vehicle body roof (compressed by the vehicle body roof)
[Problem] To provide an antenna device that, even with a stand-type double case structure, can prevent deterioration of the antenna performance and simplify such structure. [Solution] Provided is an antenna device (1) that has a double case structure in which an inner case (13) is covered by an outer case (15), the inner case having an accommodation space formed therein for accommodating a coil element (12) or the like. An antenna element (14) is interposed between the outer surface of the inner case (13) and the inner surface of the outer case (15), and the antenna element (14) is electrically connected to the coil element (12) which is inside the accommodation space, while the water-tightness of the accommodation space is maintained.