| 摘要 |
A feed-forward amplifier is provided, which can implement a satisfactory linearity immediately after its activation, which has a high productivity and exhibits less long term fluctuations of its characteristics during the operation. In the feed-forward amplifier, the transfer function of a path from an input terminal to a directional coupler via a main amplifier and the transfer function of a path from the input terminal to the directional coupler via a first delay means are automatically controlled so as to be equal in amplitude but anti-phase relative to each other, and the transfer function of a path from the main amplifier to an output terminal via a second delay means and the transfer function of a path from the main amplifier to the output terminal via an auxiliary amplifier are automatically controlled so as to be equal in amplitude but anti-phase relative to each other. Still further, at the time of the activation of the feed-forward amplifier, control values of a first vector adjuster are set to values stored in a first nonvolatile memory in accordance with a temperature measured in the vicinity of the main amplifier by a first temperature sensor, and control values of a second vector adjuster are set to values stored in a second nonvolatile memory in accordance with a temperature measured in the vicinity of the auxiliary amplifier by a second temperature sensor.
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