A power amplifier circuit includes an amplifier element that amplifies a signal input to a base and outputs an amplified signal from a collector, and a variable capacitor provided between the base and the collector of the amplifier element. A power-supply voltage that varies in accordance with an envelope of amplitude of a radio-frequency signal is applied to the collector of the amplifier element, and capacitance of the variable capacitor decreases in response to an increase in the power-supply voltage input to the collector of the amplifier element.

A Doherty amplifier including a main amplifier and a peak amplifier is mounted on a package substrate. A low noise amplifier is further mounted on the package substrate. A transmit/receive switch switches in terms of time between a transmission connection state in which an output signal of the Doherty amplifier is supplied to an antenna and a reception connection state in which a signal received by the antenna is inputted to the low noise amplifier.

A PA module includes: a multilayer substrate having a ground pattern layer connected to a ground of a power source; amplifier transistors disposed on the multilayer substrate; a bypass capacitor having one end connected to the collector of the amplifier transistor; a first wiring line connecting the emitter of the amplifier transistor and the ground pattern layer to each other; a second wiring line connecting the emitter of the amplifier transistor and the ground pattern layer to each other; a third wiring line connecting the other end of the bypass capacitor and the ground pattern layer to each other; and a fourth wiring line formed between the amplifier transistor and the ground pattern layer and between the bypass capacitor and the ground pattern layer and connecting the first wiring line and the third wiring line to each other.

Charge-pump tracker circuitry is disclosed having a first switch network configured to couple a first capacitor between a voltage input terminal and a ground terminal during a first charging phase and couple the first capacitor between the voltage input terminal and a pump output terminal during a first discharging phase. A second switch network is configured to couple the second capacitor between the voltage input terminal and the ground terminal during a second charging phase and couple the second capacitor between the voltage input terminal and the pump output terminal during a second discharging phase. A switch controller is configured to control the first switch network and the second switch network so that the first discharging phase and the second discharging phase are in unison in a parallel mode and so that the first discharging phase and the second discharging phase alternate in an interleaved mode.

Envelope tracking schemes for Doherty power amplifiers are provided herein. In certain embodiments, a mobile device includes a Doherty power amplifier that amplifies an RF signal for transmission on an antenna, and an envelope tracker that controls a supply voltage of the Doherty power amplifier based on an envelope of the RF signal amplified by the Doherty power amplifier. Thus, supply modulation is used to control the supply voltage of the Doherty power amplifier to achieve gains in linearity, efficiency, and/or other performance metrics. Furthermore, the Doherty power amplifiers herein can provide higher overall transmission efficiency and/or lower DC power consumption, which in turn leads to lower operating temperatures and/or improved reliability.

Envelope tracking systems for power amplifiers are provided herein. In certain embodiments, an envelope tracker is provided for a power amplifier that amplifies an RF signal. The envelope tracker includes an error amplifier that controls a voltage level of a power amplifier supply voltage of the power amplifier based on amplifying a difference between a reference signal and an envelope signal indicating an envelope of the RF signal. The envelope tracker further includes a multi-level switching circuit that generates an error amplifier supply voltage based on sensing a current of the error amplifier, and uses the error amplifier supply voltage to power the error amplifier.

An envelope tracking (ET) integrated circuit (IC) (ETIC) is provided. The ETIC is configured to generate an ET voltage based on a supply voltage(s) and provide the ET voltage to an amplifier circuit(s) for amplifying a radio frequency (RF) signal(s). Notably, the RF signal(s) may be modulated in different modulation bandwidths and the amplifier circuit(s) may correspond to different load-line impedances. Accordingly, the ETIC may need to adapt the ET voltage such that the ETIC and the amplifier circuit(s) can operate at higher efficiencies. In examples discussed herein, the ETIC is configured to determine a time-variant peak of the ET voltage and adjust the supply voltage(s) accordingly. As a result, it may be possible to improve operating efficiency of the ETIC in face of a wide range of bandwidth and/or load-line requirements.

Disclosed is a method for producing a stage for amplifying the power of a variable envelope signal including at least one amplifier. For each amplifier, a form of ideal variation in average power POUT.sub.L is selected. For each value of each setting parameter and for each average input power value, a value of an optimisation criterion is calculated on the basis of the mathematical expectation of at least one optimisation parameter. An optimum value of each setting parameter is determined and the amplification stage is produced with a number of amplifiers in parallel determined on the basis of an average output power value and with, for each amplifier, matching circuits providing the optimum values of the setting parameters. The invention also relates to an amplification stage produced in this manner.

A device for controlling spectral regrowth includes a transmission signal processor configured to generate a baseband transmission signal and a controller. The controller is configured to adjust delay of an envelope tracking path that provides a supply voltage to an envelope tracking power amplifier included in a transmission path that generates a radio frequency (RF) transmission signal from the baseband transmission signal. The controller may obtain allocation information of resource blocks included in the RF transmission signal from the transmission signal processor and may determine the delay of the envelope tracking path based on the allocation information.

A bias circuit includes a bias current circuit varying a resistance value according to a mode voltage determined according to a magnitude of an input radio frequency signal, and generating a bias current that is controlled according to the variation of the resistance value; a bias voltage circuit generating a bias voltage that is adjusted according to a change in a power source voltage and supplying the bias voltage to an amplifying circuit; and a bias transfer circuit supplying the bias current to a base node of the amplifying circuit and blocking an input of the radio frequency signal from the base node.