Abstract: An amplifier may include first and second terminals to receive first and second input signals and a differential amplifier providing differential amplification of the first and second input signals. The differential amplifier may include a first differential amplifier stage to receive the first input signal and a second differential amplifier stage to receive the second input signal. The amplifier may further include a first bias circuit to bias the first differential amplifier stage, where the first bias circuit is connected to the second input terminal to provide anti-phase bias control of the first differential amplifier stage. The amplifier may further include a second bias circuit to bias the second differential amplifier stage, where the second bias circuit is connected to the first input terminal to provide anti-phase bias control of the second differential amplifier stage.

Abstract: A power amplifier comprising a power stage comprises a voltage detection circuit configured to detect an output voltage of the power stage, a current detection circuit configured to detect an output current of the power stage, a control voltage generation circuit configured to generate a control voltage substantially proportional to the detected output voltage and the detected output current, and a control circuit configured to decrease an output power of the power stage when the control voltage exceeds a predetermined value.

Abstract: A power amplifier comprising a power stage comprises a voltage detection circuit configured to detect an output voltage of the power stage, a current detection circuit configured to detect an output current of the power stage, a control voltage generation circuit configured to generate a control voltage substantially proportional to the detected output voltage and the detected output current, and a control circuit configured to decrease an output power of the power stage when the control voltage exceeds a predetermined value.

Abstract: A radio frequency (RF) power amplifier comprises an output stage amplifying circuit and a counterpart waveform generator. The output stage amplifying circuit receives a first waveform through an input node and amplifies the first waveform so as to output an amplified waveform through an output node. The counterpart waveform generator generates a second waveform corresponding to a portion of frequency components of the first waveform. The output stage amplifying circuit and the counterpart waveform generator are electrically coupled such that the second waveform is applied to the input node of the output stage amplifying circuit to substantially compensate the portion of frequency components of the first waveform.

Abstract: A radio frequency (RF) power amplifier comprises an output stage amplifying circuit and a counterpart waveform generator. The output stage amplifying circuit receives a first waveform through an input node and amplifies the first waveform so as to output an amplified waveform through an output node. The counterpart waveform generator generates a second waveform corresponding to a portion of frequency components of the first waveform. The output stage amplifying circuit and the counterpart waveform generator are electrically coupled such that the second waveform is applied to the input node of the output stage amplifying circuit to substantially compensate the portion of frequency components of the first waveform.

Abstract: A power amplifier circuit for amplifying an envelope modulated Radio Frequency (RF) signal with improved linearity and efficiency includes a power amplifier, and a variable load matching circuit coupled to an output port of the power amplifier. The input impedance of the variable load matching circuit is changed such that an output power of the power amplifier is at a first output power level, or a second output power level which is higher than the first output power level.

Abstract: A power amplifier circuit for amplifying an envelope modulated Radio Frequency (RF) signal with improved linearity and efficiency includes a power amplifier, and a variable load matching circuit coupled to an output port of the power amplifier. The input impedance of the variable load matching circuit is changed such that an output power of the power amplifier is at a first output power level, or a second output power level which is higher than the first output power level.

Abstract: A power amplifier comprises a common source amplification stage and a first common gate amplification stage. The common source amplification stage includes a common source transistor for receiving a radio frequency (RF) input signal via a gate. The first common gate amplification stage is connected in cascode between a variable supply voltage source and the common source amplification stage, and amplifies an output of the common source amplification stage. The first common gate amplification stage includes a first common gate transistor, and a first gate bias controller configured to generate a first divided voltage based on a variable supply voltage of the variable supply voltage source, and to supply a first gate bias voltage generated by buffering the first divided voltage to a gate of the first common gate transistor.

Abstract: A power amplifier including a MOSFET including a source supplied with a first DC power, a gate connected to an RF input signal, and a drain connected to a power supply terminal of an RF power amplification unit; a supply voltage modulation control unit that determines a DC gate voltage of the MOSFET based on an envelope of the RF input signal; and a bypass circuit connected between the drain and the power supply terminal. The MOSFET outputs a second DC power via the drain and amplifies the RF input signal based on a third DC power substantially identical to a differential between the first and the second DC power, and also outputs an RF power via the drain. The bypass circuit receives and rectifies the RF power to supply a recycled DC power to the power supply terminal of the RF power amplification unit.

Abstract: A power amplifier includes first and second amplification stages. The first amplification stage is configured to amplify a radio frequency (RF) input signal. The second amplification stage includes at least one transistor configured to amplify an output of the first amplification stage, the second amplification stage being configured to have a capacitance between a gate of the at least one transistor and a first power supply voltage. The capacitance automatically varies with amplitude of the output of the first amplification stage.

Abstract: A power amplifier comprises a common source amplification stage and a first common gate amplification stage. The common source amplification stage includes a common source transistor for receiving a radio frequency (RF) input signal via a gate. The first common gate amplification stage is connected in cascode between a variable supply voltage source and the common source amplification stage, and amplifies an output of the common source amplification stage. The first common gate amplification stage includes a first common gate transistor, and a first gate bias controller configured to generate a first divided voltage based on a variable supply voltage of the variable supply voltage source, and to supply a first gate bias voltage generated by buffering the first divided voltage to a gate of the first common gate transistor.

Abstract: A power amplifier including a MOSFET including a source supplied with a first DC power, a gate connected to an RF input signal, and a drain connected to a power supply terminal of an RF power amplification unit; a supply voltage modulation control unit that determines a DC gate voltage of the MOSFET based on an envelope of the RF input signal; and a bypass circuit connected between the drain and the power supply terminal. The MOSFET outputs a second DC power via the drain and amplifies the RF input signal based on a third DC power substantially identical to a differential between the first and the second DC power, and also outputs an RF power via the drain. The bypass circuit receives and rectifies the RF power to supply a recycled DC power to the power supply terminal of the RF power amplification unit.

Abstract: A radio-frequency (RF) switch comprises first and second heterojunction bipolar transistors (HBTs) that control transmission of an RF input signal between an input terminal and an output terminal. In some embodiments, the RF input signal is transmitted from the input terminal to the output terminal where the first and second HBTs are turned ON, and otherwise the RF input signal is not transmitted from the input terminal to the output terminal.

Abstract: A power amplifier includes first and second amplification stages. The first amplification stage is configured to amplify a radio frequency (RF) input signal. The second amplification stage includes at least one transistor configured to amplify an output of the first amplification stage, the second amplification stage being configured to have a capacitance between a gate of the at least one transistor and a first power supply voltage. The capacitance automatically varies with amplitude of the output of the first amplification stage.

Abstract: A device includes: a power amplifier, including a supply voltage terminal, an input port and an output port, and the power amplifier being configured to receive a supply voltage at the supply voltage terminal, an input signal through the input port, to amplify the received input signal, and to output an amplified output signal through the output port; a variable impedance matching circuit having an input terminal connected to the output port of the power amplifier, and having an output terminal for being connected to a load; and a controller including a voltage measuring unit configured to measure the supply voltage, to compare the measured supply voltage with a threshold voltage, and to control the variable impedance matching circuit based on a result of the comparison so as to adjust a load impedance seen by the power amplifier at its output port.

Abstract: An amplification device includes a series combination of a driver stage, an output terminal matching network, and a secondary amplification stage. The driver stage includes a driver amplifier and an output matching network. The secondary amplification stage includes a parallel combination of an impedance transformation network and a main amplification stage. The main amplification stage includes a plurality of main amplification branches in parallel with each other, and an input matching network in series with the parallel combination. Each main amplification branch includes a main amplifier, and input and output impedance matching networks. A control circuit supplies activation signals to the main amplification branches to selectively turn them on and off. The device has no switches in the path of the signal that is amplified. In at least one operating mode, the control circuit turns on at least two of the main amplification branches at the same time.

Abstract: An amplification device includes a series combination of a driver stage, an output terminal matching network, and a secondary amplification stage. The driver stage includes a driver amplifier and an output matching network. The secondary amplification stage includes a parallel combination of an impedance transformation network and a main amplification stage. The main amplification stage includes a plurality of main amplification branches in parallel with each other, and an input matching network in series with the parallel combination. Each main amplification branch includes a main amplifier, and input and output impedance matching networks. A control circuit supplies activation signals to the main amplification branches to selectively turn them on and off. The device has no switches in the path of the signal that is amplified. In at least one operating mode, the control circuit turns on at least two of the main amplification branches at the same time.

Abstract: A multi-mode power amplifier and an electronic device including the amplifier are described.

Abstract: A voltage-insensitive circuit includes a second circuit, and a biasing means for providing a constant bias current to the second circuit, the bias current being insensitive to power fluctuations of the voltage-insensitive circuit.

Abstract: A multi-mode power amplifier and an electronic device including the amplifier are described.