Patent ID: 9106184
Filing Date: 2015-08-11
Classification: H03F

Abstract:
1. A high-frequency amplifier having a high-frequency amplifying unit that amplifies and outputs a modulated analog signal, the high-frequency amplifier comprising: an envelope signal acquisition unit for acquiring an envelope signal of the modulated analog signal; a control signal generator circuit that generates a control signal; and a diode clamped variable power circuit that is connected to a supply terminal of the high-frequency amplifying unit, and functions as a power circuit of the high-frequency amplifying unit, wherein the diode clamped variable power circuit includes a plurality of diode clamped circuits each having a DC power supply, a diode, and a power transistor, wherein each of the diode clamped circuits has an output terminal that outputs a voltage of the DC power supply through the diode, wherein the diode clamped variable power circuit is structured to stack the clamped circuits in a multistage manner, and the plurality of diode clamped circuits are connected in a multistage manner through the respective output terminals so that the plurality of power transistors are connected in series with the supply terminal, wherein the DC power supplies corresponding to the respective power transistors are connected in series with one another in a multistage manner, wherein the control signal generator circuit generates the control signal that is changed according to a linear function on the basis of a magnitude of the envelope signal, and wherein the power transistor of each of the diode clamped circuits is controlled according to the control signal which is changed according to the linear function, individually, to change the supply voltage of the high-frequency amplifying unit according to the magnitude of the modulated analog signal.