| 摘要 |
PURPOSE:To improve amplification efficiency and to obtain a linear characteristic by canceling the fluctuation of a passing phase caused by the change of inputted power by changing the fluctuation into gate current. CONSTITUTION:The high frequency signal from an input terminal 1 is amplified in an electric field effect transistor 3 and is outputted to an output terminal 2 via a matching circuit 5. At this time, the power of an input high frequency signal is detected in a power detection circuit 11 and is transmitted to a control circuit 12. By the change of the passing phase caused by changing the resistance value of a variable resistor 13 inserted between a gate terminal 9 and a bias power source 6 according to inputted power based on the information, the change of the passing phase caused by the change of inputted power is canceled and the fluctuation of the phase is suppressed. Therefore, even if an amplifier is operated by a high efficiency AB class, the change of the passing phase is suppressed and a linear characteristic can be obtained. |
