| 摘要 |
PURPOSE:To use earth station reception equipments the same in specification in an object area with nearly the same inoperation rate by forming the radiation pattern of a satellite antenna of a down-link similar to the district distribution of rainfall attenuation. CONSTITUTION:A radiation pattern of a shaped beam antenna in a down-link frequency of a satellite 2 is an elliptic beam up to -5dB and its center is directed to Kochi - Kagoshima having a large rainfall attenuation. The beam is shaped to form a projected side beam of nearly -7dB toward Hokkaido having a few rainfall attenuation. Then the difference in the reception performance figure deviation between cities except Naha is 2.7dB and the required antenna diameter ratio is within 2<1/2>, and it is possible to offer the broadcast service with nearly the same inoperation rate to recipients of each city except Naha by using the antennas the same in diameter D.
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