| 摘要 |
<p>PROBLEM TO BE SOLVED: To widen the communicable area, where communication connection is made with a radio communication apparatus used in tunnel, by improving the characteristics of an antenna provided in a fire extinguisher housing device.SOLUTION: An antenna 18 is provided in a fire extinguisher housing device 12 installed in a tunnel at a predetermined interval. Between a radio connection box for fire fighting and a radio connection box for police on the outside of tunnel pit mouth, connection is made from a duplexer via the fire extinguisher housing devices sequentially by a coaxial power supply cable, and the antenna 18 is connected via a splitter. The fire extinguisher housing device 12 has an opening formed in the fire extinguisher door 30, and in which the antenna 18 is installed. A reflector 38 is arranged on the back of the antenna 18, i.e., the inside of the fire extinguisher door 30, and an antenna cover 34 is arranged so as to cover the front of the antenna 18, i.e., the outside of the opening in the fire extinguisher door 30.</p> |
