| 摘要 |
PROBLEM TO BE SOLVED: To prevent the quality of broadcast radio waves for retransmission, because a failure such as oscillation occurs due to the wraparound of a transmission signal in a broadcast signal repeating apparatus for receiving and amplifying the broadcast radio waves of a prescribed channel and retransmitting the amplified received signal, without having to convert the frequency. SOLUTION: In the repeating apparatus in which amplifier circuits 4 and 8 amplify a broadcast signal of a prescribed channel received by a receiving antenna 2 and a transmitting antenna 10 retransmits the broadcast signal, detection circuits 21 and 22, respectively detect a peak value (P) and an average amplitude (A) of the amplitude of a transmission signal; and an abnormality determining circuit 23, a smoothing circuit 24 and an output circuit 25 control the gain of the repeater via a gain control circuit 6, such that the ratio (P/A) of the respective parameters (P and A) do not exceed a threshold. Consequently, oscillation is prevented more surely than the conventional device for performing gain control only by average amplitude (A) and a peak value (P) so that the quality of the broadcast signal (radio waves) can be prevented from deteriorating. COPYRIGHT: (C)2010,JPO&INPIT |
