Amplifier

Abstract

Abstract An amplifier for amplifying a high frequency signal comprises an input matching circuit, an output matching circuit, an FET whose gate and drain are connected to the input matching circuit and the output matching circuit, respectively, and a gate voltage control circuit for controlling a gate voltage in accordance with a power of the high frequency signal, which is connected to a junction node of an output end of the input matching circuit and the gate of the FET. The gate voltage control circuit comprises a diode whose anode is connected to the gate, a capacitor disposed between a cathode of the diode and ground, and a gate bias setting circuit whose output is connected to a junction node of the diode and the capacitor. The gate bias setting circuit outputs a control voltage corresponding to a power of the high frequency signal. As the result, the matching of the output matching circuit is not deviated and a linearity of the output power to the input power is kept in a good state, resulting in an amplifier with high efficiency.

Inventors

• 👤 Sasaki c/o Mitsubishi Denki K. K. Yoshinobu

Bibliographic Details