A power amplifier circuit includes a power splitter, a first amplifier configured to output a first amplified signal from a first output terminal, and a second amplifier configured to output a second amplified signal from a second output terminal. The power amplifier circuit further includes a first termination circuit connected between the first output terminal and the second output terminal, a first transmission line, a second transmission line, a second termination circuit connected between another end of the first transmission line and another end of the second transmission line, and a power combiner.

An amplifier system including a push-pull power amplifier having an input to receive a radio frequency (RF) input signal and an output, the push-pull power amplifier being configured to amplify the RF input signal and provide at the output an RF output signal that is an amplified version of the RF input signal, a switchable shunt capacitance switchably connected between a load-line connected to the output of the push-pull power amplifier and a reference potential, and a switch configured to selectively connect the switchable shunt capacitance to the reference potential and disconnect the switchable shunt capacitance from the reference potential to vary an impedance of load-line.

A power amplifier circuit includes a power splitter, a first amplifier configured to output a first amplified signal from a first output terminal, and a second amplifier configured to output a second amplified signal from a second output terminal. The power amplifier circuit further includes a first termination circuit connected between the first output terminal and the second output terminal, a first transmission line, a second transmission line, a second termination circuit connected between another end of the first transmission line and another end of the second transmission line, and a power combiner.

In an RFIC provided in a semiconductor device according to an embodiment, a low-noise amplifier (41) for reception and a power amplifier (11) for transmission are connected to a common antenna connection terminal (5). Between the antenna connection terminal (5) and an LNA (41), a circuit (31) is connected to be used for impedance matching, and a semiconductor switch (SW1) is connected in parallel with the circuit (31).

An electronic device is provided. The electronic device includes a communication module and a processor electrically connected to the communication module, wherein the communication module includes an antenna configured to transmit and receive a communication signal, a sensor configured to measure an impedance of the antenna, and a first matching circuit and a second matching circuit electrically connected to the antenna, and the processor is configured to receive information on the impedance of the antenna from the sensor, check control information on at least one of the first matching circuit and second matching circuit corresponding to the impedance of the antenna at least partially based on the received information on the impedance of the antenna, and transmit control information generated at least partially based on the checked control information to at least one of the first matching circuit and the second matching circuit corresponding to the control information.

A power amplifier circuit includes N (N is an integer equal to or greater than 2) power amplifier circuit cores, which in operation, amplify power of an input signal, N inductors, which in operation, are connected to the N power amplifier circuit cores, and ring-oscillator-type transconductance (gm) generation circuitry, which in operation, generates transconductance (gm) for compensating power loss of the N inductors.

A low noise amplifier (LNA) system for amplifying a plurality of carriers includes a first amplifier circuit that generates a first radio-frequency (RF) output signal by amplifying a first input RF signal corresponding to a first frequency band, the first amplifier circuit having a first input impedance, and a second amplifier circuit that generates a second RF output signal by amplifying the first input RF signal when the system is in a first multi-output mode, a second input impedance of the second amplifier having a first impedance value when the system is in the first multi-output mode. The LNA system further includes a first impedance controller that maintains the second input impedance of the second amplifier circuit at a second impedance value when the apparatus is in a mode other than the first multi-output mode. The second impedance value is substantially the same as the first impedance value.

A switching power amplifier includes logic circuitry that generates first and second components of a differential signal, based on received amplitude code and a delayed version of the same. The amplitude code includes a sign and a magnitude. When the sign is positive, a first logic path is configured to generate the first component based on the received amplitude code and the second logic path is configured to generate the second component based on the delayed amplitude code. When the sign is negative, the first logic path is configured to generate the first component based on the delayed amplitude code and the second logic path is configured to generate the second component based on the received amplitude code. The switching power amplifier further includes a differential-to-single ended conversion circuit configured to generate a single-ended signal based on the differential signal.

An RF power amplifier includes an amplifier device and a shunt-inductance circuit. The amplifier device includes a substrate, a combining node lead, first and second amplifier dies coupled to the substrate, and first and second output circuits. The first and second amplifier dies are configured to amplify first and second input RF signals, respectively, to produce first and second output RF signals at first and second output terminals, respectively. The first output circuit includes a first inductive path connecting the first output terminal to the lead. The second output circuit includes a second inductive path connecting the second output terminal to the lead. The lead is configured to combine the first and second output RF signals to produce a third output RF signal. The shunt-inductance circuit is coupled between the first output terminal and a ground reference.

Aspects of the subject disclosure may include a Doherty amplifier that includes a carrier amplifier having an output terminal, an output network coupled to the output terminal, and a peaking amplifier, wherein the output network comprises a non-linear reactance component, and wherein the non-linear reactance component changes an effective impedance of a load presented to the carrier amplifier when the peaking amplifier is off. Other embodiments are disclosed.