| 摘要 |
<P>PROBLEM TO BE SOLVED: To control the level difference between a television broadcast signal and a local oscillation signal to be wirelessly transmitted to a proper value, in a millimeter-wave transmitting apparatus that uses the local oscillation signal of a millimeter-wave band to up-convert the television broadcast signal and wirelessly transmits the up-converted television broadcast signal and the local oscillation signal. <P>SOLUTION: In order to allow a self-heterodyne type receiving apparatus 30 to normally restore a CATV signal before being up-converted by a transmitting apparatus 10, it is necessary to control a level difference between the CATV signal and a local oscillation signal in a reception signal to a proper value (about 15 dB). Then, the transmitting apparatus 10 comprises an AGC circuit 14 for performing level adjustment on the CATV signal, in such a way that the level difference between a pilot signal, corresponding to the CATV signal before up-converting and the local oscillation signal, becomes the targeted level difference. As a result, the level difference between the up-converted CATV signal and the local oscillation signal is controlled to a proper value, so that the receiving apparatus 30 can carry out down-conversion in a normal manner. <P>COPYRIGHT: (C)2010,JPO&INPIT |
