| 摘要 |
PURPOSE:To allow a reverse transmission signal to pass without loss and to make bidirectional transmission possible by providing a filter having a selective frequency passage characteristic in parallel with a voltage feedback circuit between a base and a collector. CONSTITUTION:In case of forward transmission, the input signal of a base terminal 1 cannot reach a collector terminal 9 through a filter because the input signal is in the stop band of the filter 2, and the input signal is amplified by a wide band amplifier 10 and is outputted to the terminal 9. In case of reverse transmission, the input signal of the terminal 9 is outputted to the terminal 1 without loss through the filter because the input signal is in the pass band of the filter. |
