| 摘要 |
<p>An outer peripheral wall and an inner peripheral wall are formed in the lower part of a shark-fin antenna case (10). The lower end surface of the inner peripheral wall is bonded to the upper surface of an insulating base (20) in an antenna base (11) arranged on the lower surface of the antenna case (10). Thus, an antenna assembly can be housed in the antenna case (10) which is constructed to be waterproof. The antenna assembly is provided with: an element holder (12) that is arranged upright on the antenna base (11); an umbrella-shaped element (13) that is fixed to the top part of the element holder (12) in such a way that the rear part thereof is positioned above the insulating base (20); an amplifier substrate (16) for amplifying a reception signal of the umbrella-shaped element; and a coil (14) that causes the umbrella-shaped element (13) to resonate at the specified frequency. Therefore, the antenna base can be formed without requiring a strengthening member.</p> |
