| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a digital broadcast retransmission system for retransmitting a broadcast radio wave from a broadcast station to areas incapable of directly receiving the broadcast radio wave from the broadcast station that can retransmit the broadcast radio wave via a plurality of transmission antennas over a wide range and set the same frequency of the retransmitted radio wave as the frequency of the radio wave transmitted from the broadcast station. <P>SOLUTION: Transmitting a received signal from a reception antenna 10 to the two transmission antennas 20, 30 for retransmitting the broadcast radio wave via optical fibers 22, 32 enables the two transmission antennas 20, 30 to retransmit the received signal over the wide range without causing loop oscillation or the like in a transmission path. A radio wave interference area C into which the broadcast radio waves from the transmission antennas 20, 30 both arrive at proper levels can restore the broadcast program without being adversely affected by interference between the broadcast radio waves from the transmission antennas 20, 30 by adjusting the lengths La, Lb of the optical fibers 22, 32 used for the transmission of the received signal to suppress the delay time difference of each broadcast radio wave within a permissible range. <P>COPYRIGHT: (C)2007,JPO&INPIT |
