| 摘要 |
PROBLEM TO BE SOLVED: To provide a system where a transmission loss can be reduced, the transfer of noise with transmission line installing environment is eliminated and the danger of lightning to a transmission line itself is eliminated by setting the signal transmission lines among a reception antenna installed on the summit and a light source and a photoelectric converter, which are installed in a radio wave dead zone area and the like, to optical fibers. SOLUTION: A photoelectric modulator 2 modulating the intensity of incident light and emitting light in accordance with the voltage of an electrtic signal is connected to the reception antenna 1, the light source 3 and the photoelectric converter 4 to the photoelectric modulator 2 and a transmission line system to the photoelectric converter 4. In the system, the signal transmission lines among the reception antenna 1 installed on the summit and the light source 3 and the photoelectric converter 4, which are installed in the radio wave dead zone area or a place near it, are set to be the optical fibers 6. The output electric signal of the photoelectric converter 4 passes through a coaxial cable 12, is transmitted through a leakage coaxial cable 7 laid in the radio wave dead zone area such as a tunnel and an underground shopping center and it is radiated again on pertinent space as an electromagnetic wave through the leakage coaxial cable 7. |
