| 摘要 |
PROBLEM TO BE SOLVED: To reduce power consumption by making a distortion compensation circuit small. SOLUTION: A passive circuit consisting of a capacitor 5, a resistor 6 and an inductor 7, and a characteristic improving circuit 10 consisting of a source connected to the passive circuit and a grounded drain FET 8 are connected between input matching circuits 2 and 3 of a nonlinear amplification element (FET 1) for amplification. In the characteristic improving circuit 10, the gate capacitance increases in the FET 8, a pass gain increases and a pass phase decreases in accordance with an increase in an input level. A phase characteristic and a distortion characteristic of an amplifier at a certain output level are improved by compensating a characteristic of a FET 1 with the characteristic. Since the characteristic improving circuit 10 is formed on the same substrate on which the input matching circuits 2 and 3 are formed, a semiconductor amplifier can be small. Power consumption does not increase because a direct current does not flow due to the capacitor 5. COPYRIGHT: (C)2004,JPO
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