| 摘要 |
PROBLEM TO BE SOLVED: To provide a traveling wave tube amplifier capable of improving input and output linearity when inputting a large RF signal, and reducing power consumption when inputting a small RF signal. SOLUTION: In this traveling wave tube amplifier, a power source is supplied from a high voltage power source 1 to the respective electrodes of a traveling wave tube 2 so that a high frequency signal Pi can be amplified to Po by the traveling wave tube 2. The level of the high frequency signal Pi inputted to the traveling wave tube 2 is detected from the currents of a third collector 25c of the traveling wave tube 2. Also, the currents of a collector 25c are uniquely decided according to the level of the high frequency signal Pi. This current detection is performed by a collector current detecting circuit 12 using an insulating hall device. A data processing part 13 which receives the collector currents controls an anode voltage Va of the traveling wave tube 2 so that the amplified output Po of the traveling wave tube 2 can be backed off by fixed quantity, preferentially 5dB from a saturated output.
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