| 摘要 |
<p>PURPOSE:To reduce a bad influence on transmission signal, even without the presence of vacant transmission band, by cancelling the monitoring signal through the application of inverse monitoring signal of the antiphase and the same amplitude as the monitoring signal extracted from superimposed signals to them. CONSTITUTION:A superimposed signal is received at an AGC73. The superimposed signal is split into two at a distributor 61 and filtered at a band pass filter 71. The phase delayed at the band pass filter 71 is advanced and the phase is inverted for the signal, which is represented at the output of a PLL oscillator 72 as an inverse monitoring signal 94. This inverse monitoring signal 94 and the monitoring signal 93 from the output 611 of the branch device 61 are added at a cancellation circuit 81, the monitoring signal 93 is disappeared, and only the transmission signal 91 is fed to one terminal 51.</p> |
