| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that a satisfactory receiving level can not be kept in the environment that electromagnetic shields exist around in a conventional broadband leakage coaxial cable. SOLUTION: In the leakage coaxial cable in which a plurality of leaked electromagnetic field formation slots are provided in the shape of array on the outer conductor of the coaxial cable and the excitation coefficient distribution of the slot array with respect to a leaked electric field component in the peripheral direction of a cable axis has a period P in an axial direction, is inverted at the interval of P/2 and is symmetrical to the center line, among spatial harmonic formed from the slot array in at least one or more frequencies within a frequency band to be used, two odd-order spatial harmonic waves are made exist as fast waves and between the two spatial harmonic, the odd- order spatial harmonic of a high degree next to the higher degree is approximately suppressed. At the same time, all the spatial harmonic to be fast waves of a degree lower than the suppressed spatial harmonic are approximately suppressed except for the two odd-order spatial harmonic to exist, and a guide wavelength reduction rateνof the leakage coaxial cable is settled within a range of 0.4<ν≤1.0. COPYRIGHT: (C)2003,JPO
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