| 摘要 |
PROBLEM TO BE SOLVED: To provide an intrabuilding booster 1 for a bidirectional CATV system which has no C/N deterioration and can save energy when operating up-stream signals at a high level. SOLUTION: An amplifier circuit for up-stream signals 3 comprises a first amplifier 30, a passing line 31 connected to the first amplifier 30 in parallel, a selection means 32 for selecting and outputting an up-stream signal in the CATV system via either the first amplifier 30 connected in parallel or the passing line 31, a level adjusting means 33 connected to an output of the selection means 32, and a second amplifier 34 connected to the output of the level adjusting means 33. By selectively applying a DC voltage to the first amplifier 30 and the selection means 32, either the first amplifier 30 connected in parallel or the passing line 31 is selected. COPYRIGHT: (C)2005,JPO&NCIPI
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