| 摘要 |
PROBLEM TO BE SOLVED: To avoid the same channel fault without using an apparatus for a common-listening system while improving the deterioration of a signal quality. SOLUTION: An antenna device has an existing first UHF antenna 10 receiving a television broadcasting in a plurality of channels in a UHF band, and a second UHF antenna 11 receiving the television broadcasting generating the same channel fault in the UHF band by different channels. The receiving signal of the second UHF antenna 11 is amplified by a preamplifier 12 and supplied to a mixer 13 together with the receiving signal of the first UHF antenna 10. A DC power supply overlapped to a coaxial cable is separated by a power-supply extractor 15 and supplied to the preamplifier 12. Accordingly, the antenna device can be manufactured in which the same channel fault is avoided without using the apparatus for the common-listening system while the deterioration of the signal quality can be prevented by improving a CN ratio (the Carrier to Noise ratio). COPYRIGHT: (C)2007,JPO&INPIT
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