| 摘要 |
<p>The present invention relates to an antenna of a manhole monitoring system, and more particularly, to an antenna structure of a manhole monitoring system for reducing the size of an antenna used in a relay terminal and a collecting terminal that detects the position, state and history of a manhole using a sensor set inside the manhole and wirelessly transmits the detection result to an external device using an RF communication module and improving the characteristic of the antenna.</p> |
