| 摘要 |
PROBLEM TO BE SOLVED: To comparatively inexpensively transmit video signals hardly causing attenuation by disposing a transmission antenna of a video camera between two parallel signal lines arranged along a guide rail thereby transmitting the signal of the video camera moving on the guide rail. SOLUTION: Two bare two-wire feeders 15 and 15 are arranged along with a guide rail 14 and a transmission antenna 12 of a video camera 13 is disposed between the two-wire feeders 15 and 15. When the inter-line distance of parallel two-wire feeders 15 and 15 is defined as D(cm) and a lead wire radius is defined as d(cm), a characteristic impedance Z0 of parallel two-wire feeders 15 and 15 is 277 log (D/d), an attenuation coefficientαis [0.036. f(MHz)1/2}/Z0.d(c/ m)](dB/m). When the distance D between the parallel wore feeders 15 and 15 is expanded, the attenuation coefficientαis reduced. In order to reduce the spatial spread of energy influence or curve of an external electric/magnetic field, the condition of D<λ<8 (λis a transmission wavelength) is generally established.
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