| 摘要 |
<p>PURPOSE:To realize the reception superior in an SN ratio. CONSTITUTION:A first antenna wire 1 wound clockwise and a second antenna wire 20 wound counterclockwise are provided along a passage in a gate part through which a person 3 carrying a radio ID card 2 passes. The antenna wires 1 and 20 are electrically connected in parallel and the respective antenna wires 1 and 20 receive signals from the radio ID card and the like. Thus, external electromagnetic wave noise is removed, the feeble signal can be detected and the shift of an object can be detected with a high probability.</p> |
