Provided is a power amplification module that includes: a first transistor, a first signal being inputted to a base thereof; a second transistor, the first signal being inputted to a base thereof and a collector thereof being connected to a collector of the first transistor; a first resistor, a first bias current being supplied to one end thereof and another end thereof being connected to the base of the first transistor; a second resistor, one end thereof being connected to the one end of the first resistor and another end thereof being connected to the base of the second transistor; and a third resistor, a second bias current being supplied to one end thereof and another end thereof being connected to the base of the second transistor.

A decoder for a wireless charging transmitter and a wireless charging transmitter using the same are provided in the present invention. In order to adapt the wide range of the received signal from the wireless charging receiver, which usually results in the error of the decode, the feedback circuit of the wireless charging transmitter is changed, so that the signal in a certain swing is amplified by an original gain, and the signal out of the certain swing is amplified by a limited gain. Therefore, the amplified signal is able to show the characteristic of the original received signal. Thus, the accuracy of decoding is increased.

An apparatus is disclosed for phase-shifting signals. In example implementations, the apparatus includes a phase shifter. The phase shifter includes a first port, a second port, a vector modulator coupled to the first port, and a signal phase generator. The signal phase generator includes multiple amplifiers coupled between the vector modulator and the second port. The signal phase generator also includes multiple capacitors that couple the multiple amplifiers together to form a loop. Each respective capacitor of the multiple capacitors is coupled between a respective pair of consecutive amplifiers of the multiple amplifiers to form the loop.

Apparatus and methods for a multiclass, broadband, no-load-modulation power amplifier are described. The power amplifier (500) may include a main amplifier (532) operating in a first amplification class and a plurality of peaking amplifiers (536, 537, 538) operating in a second amplification class. The main amplifier (532) and peaking amplifiers (536, 537, 538) may operate in parallel on portions of signals derived from an input signal to be amplified. The main amplifier (532) may see no modulation of its load impedance between a fully-on state of the power amplifier (all amplifiers amplifying) and a fully backed-off state (peaking amplifiers idle). By avoiding load modulation, the power amplifier (500) can exhibit improved bandwidth and efficiency compared to conventional Doherty amplifiers.

A high-frequency signal transmission-reception circuit includes a plurality of band pass filter groups each including a plurality of band pass filter pairs; a first switch including a plurality of band pass filter-side terminal groups each including a plurality of band pass filter-side terminals, and an antenna-side terminal group; a plurality of couplers configured to output respective signal strengths of high-frequency signals transmitted on a plurality of transmission paths; and a second switch including an input terminal group electrically connected to the plurality of couplers, and an output terminal configured to output a detection signal output from one of the plurality of couplers. The first switch electrically connects one band pass filter-side terminal in one band pass filter-side terminal group and one antenna-side terminal, and also electrically connects one band pass filter-side terminal in another band pass filter-side terminal group and another antenna-side terminal.

A power supply circuit in a wireless communications system includes an envelope tracking modulator coupled to a first power amplifier circuit and a second power amplifier circuit, so that the power supply circuit supplies power to the first power amplifier circuit and the second power amplifier circuit. When a transmit signal output by a processor is within a first bandwidth range, the power supply circuit supplies power to the first power amplifier circuit, and the first power amplifier circuit amplifies power of the transmit signal. When the transmit signal output by the processor meets a second bandwidth range, the power supply circuit supplies power to the second power amplifier circuit, and the second power amplifier circuit amplifies the transmit signal.

A Doherty amplifier includes: a first amplifier to amplify a first signal as an auxiliary amplifier in a case where a frequency of each of the first signal and a second signal is a first frequency, and amplify the first signal as a main amplifier in a case where the frequency of each of the first signal and the second signal is a second frequency; a second amplifier to amplify the second signal as a main amplifier in a case where the frequency of each of the first signal and the second signal is the first frequency, and amplify the second signal as an auxiliary amplifier in a case where the frequency of each of the first signal and the second signal is the second frequency; and a combiner to synthesize the first signal amplified by the first amplifier and the second signal amplified by the second amplifier.

An outphasing amplifier includes a first amplifier configured to amplify a first signal, a second amplifier configured to amplify a second signal of which a phase difference from the first signal changes, and a synthesizer that has a first transmission line through which a third signal output from the first amplifier passes, a second transmission line through which a fourth signal output from the second amplifier passes, a first coupling circuit that is separately provided from the first transmission line and is coupled to the first transmission line, a second coupling circuit that is separately provided from the second transmission line and coupled to the second transmission line, and a node that synthesizes the third signal having passed through the first transmission line and the fourth signal having passed through the second transmission line.

Reconfigurable output baluns for wideband push-pull amplifiers are disclosed. In certain embodiments, a mobile device includes a transceiver that generates a first radio frequency signal of a first frequency band and a second radio frequency signal of a second frequency band, and a front-end system including a push-pull power amplifier that selectively amplifies one of the first radio frequency signal or the second radio frequency signal based on a band control signal. The push-pull power amplifier includes an input balun, an output balun, and a pair of amplifiers coupled between the input balun and the output balun. The band control signal is operable to control an impedance of the output balun.

A radio frequency module includes a module substrate; a power amplifier disposed on or over the module substrate, amplifies a radio frequency signal, and outputs the amplified radio frequency signal as the first transmission signal; a power amplifier disposed on or over the module substrate, amplifies a radio frequency signal, and outputs the amplified radio frequency signal as the second transmission signal; a temperature sensor disposed on or over the module substrate; and a PA control circuit disposed on or over the module substrate and controls amplification operations of the power amplifiers according to a measurement value of the temperature sensor. The maximum output power of the power amplifier is greater than the maximum output power of the power amplifier, and the distance between the temperature sensor and the power amplifier is less than or equal to the distance between the temperature sensor and the power amplifier.