| 摘要 |
PURPOSE:To reduce an electrical noise appearing in a transmitting output amplifying circuit, by providing a signal input of frequency being different from radio frequency as an original transmitting signal, to the transmitting output amplifying circuit. CONSTITUTION:In case of being in an original transmitting state, a transmitting signal from a tansmitting signal frequency generating circuit and younger stage amplifying circuit 1 is transmitted to a transmitting output amplifying circuit 4 from a switching circuit 3, is amplified and is radiated as a transmitting radio wave from a transmitting antenna. On the other hand, when stopping the transmission temporarily, the switching circuit 3 is switched to a signal generating circuit 2 side, and a signal of the signal generating circuit 2 is transmitted to the transmitting output amplifying circuit 4. The signal from this signal generating circuit 2 is made to have frequency which is considerably separated from that of an original transmitting signal, therefore, the transmitting output amplifying circuit 4 is saturated, and gain of the transmitting output amplifying circuit 4 against an electrical noise is reduced. |
