A differential power amplifier having first and second amplifiers with first and second signal output terminals along with bias circuitry in communication with the first and second amplifiers is disclosed. The differential amplifier further includes a first output clamp coupled to the first signal output terminal and a bias control terminal of the bias circuitry, wherein the first output clamp is configured to limit voltage at the first signal output terminal to a first predetermined voltage magnitude and lower bias current to the first amplifier in response to an overvoltage at the first signal output terminal. A second output clamp is coupled to the second signal output terminal and is configured to limit voltage at the second signal output terminal to a second predetermined voltage magnitude.

The present disclosure discloses a gate voltage control circuit of an IGBT and a control method thereof. The gate voltage control circuit of the IGBT comprises a voltage control circuit, an active clamping circuit and a power amplifier circuit. A control voltage outputted by the voltage control circuit indirectly controls a gate voltage of the IGBT, so as to achieve a better control of the gate voltage of the IGBT with a smaller loss. It may prevent the active clamping circuit from a too-early response and may increase the active clamping circuit response speed; and may avoid the voltage oscillation of the collector-emitter voltage Vce and the gate voltage Vge, and may improve the reliability of the IGBTs connected in series.

The present disclosure discloses a gate voltage control circuit of an IGBT and a control method thereof. The gate voltage control circuit of the IGBT comprises a voltage control circuit, an active clamping circuit and a power amplifier circuit. A control voltage outputted by the voltage control circuit indirectly controls a gate voltage of the IGBT, so as to achieve a better control of the gate voltage of the IGBT with a smaller loss. It may prevent the active clamping circuit from a too-early response and may increase the active clamping circuit response speed; and may avoid the voltage oscillation of the collector-emitter voltage Vce and the gate voltage Vge, and may improve the reliability of the IGBTs connected in series.

An amplifier has an N number of input networks connected to an input terminal to receive an input signal, a first amplifier to amplify one output signal from the N number of input networks, a (N1) number of secondary amplifiers to amplify the remaining (N1) number of output signals, except for the one output signal, from the N number of input networks, where the amplification order of the (N1) number of secondary amplifiers is determined based on the power level of each output signal from the N number of input networks when the first amplifier is operational, an N number of output networks which are arranged, and a first bias network to supply a D.C. bias voltage to at least one of the N number of output networks. An electrical length of the first bias network is less than 90 degrees.

An amplifier has an N number of input networks connected to an input terminal to receive an input signal, a first amplifier to amplify one output signal from the N number of input networks, a (N1) number of secondary amplifiers to amplify the remaining (N1) number of output signals, except for the one output signal, from the N number of input networks, where the amplification order of the (N1) number of secondary amplifiers is determined based on the power level of each output signal from the N number of input networks when the first amplifier is operational, an N number of output networks which are arranged, and a first bias network to supply a D.C. bias voltage to at least one of the N number of output networks. An electrical length of the first bias network is less than 90 degrees.

An amplifying device includes a power amplifying unit, a power supply unit for providing the power amplifying unit with a positive power supply and a negative power supply, and a mode control unit for controlling a working mode of the power supply unit. The positive power supply and the negative power supply of the amplifying device are able to vary with an output signal thereof, which reduces the power consumption of the outputted transistors of the amplifying device, thereby improving the efficiency of the amplifying device.

An amplifying device includes a power amplifying unit, a power supply unit for providing the power amplifying unit with a positive power supply and a negative power supply, and a mode control unit for controlling a working mode of the power supply unit. The positive power supply and the negative power supply of the amplifying device are able to vary with an output signal thereof, which reduces the power consumption of the outputted transistors of the amplifying device, thereby improving the efficiency of the amplifying device.

A device includes an output circuit that includes an input port at which a signal is received, an output port at which an impedance-adjusted representation of the signal is provided, and a set of bond wires connecting the input and output ports. The device further includes first and second couplers, each including a respective coupling bond wire along the set of bond wires for inductive coupling with the set of bond wires. The first coupler is oriented relative to the distributed-element output circuit to measure forward power provided by the impedance-adjusted representation of the signal via the output port. The second coupler is oriented relative to the output circuit to measure reflected power received via the output port.

A device includes an output circuit that includes an input port at which a signal is received, an output port at which an impedance-adjusted representation of the signal is provided, and a set of bond wires connecting the input and output ports. The device further includes first and second couplers, each including a respective coupling bond wire along the set of bond wires for inductive coupling with the set of bond wires. The first coupler is oriented relative to the distributed-element output circuit to measure forward power provided by the impedance-adjusted representation of the signal via the output port. The second coupler is oriented relative to the output circuit to measure reflected power received via the output port.

An apparatus for power amplifier control is provided, applied to a multi-stage power amplifier. The apparatus controls an input voltage of an amplification triode in the first amplification stage, by using a detected current change at a base of an amplification triode in the last amplification stage, achieving control of output power and a maximum output current of the multi-stage power amplifier, greatly reducing an influence of current detection on maximum output power and maximum output efficiency of the power amplifier.