| 摘要 |
PURPOSE:To exclude the effect due to harmonic components and to improve the efficiency at the saturation by providing a broad band circulator between an output of a transistor (TR) and a parallel resonance circuit in an amplifier circuit operated at the class A or B and having the parallel resonance circuit at its output. CONSTITUTION:The broad band circulator 11 is provided between the output terminal of a field effect TR (FET) 1 and a live terminal of the parallel resonance circuit 4. With an amplitude of an input signal increased, harmonics are generated in the FET. The amplified input signal component (f) and the harmonics are fed respectively to an output terminal 3. The signal component (f) is fed to the output terminal 3 without being bypassed by the circuit 4, while the harmonic components are bypassed by the circuit 4 and a reflection is caused and the components are returned to the circulator 11. Then the reflected harmonic components are absorbed by the criculator 11. The reflected harmonics are absorbed in this way to attain the efficient operation.
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