A power amplifier circuit includes a power amplifier including a first transistor having a first terminal connected to a reference potential, a second terminal to which a first current and a radio-frequency signal are input, and a third terminal connected to a first power supply potential via a first inductor; a capacitor connected to the third terminal of the first transistor; a second transistor including a first terminal connected to the capacitor and the reference potential via a second inductor, a second terminal to which a second current is input and is connected to the reference potential, and a third terminal connected to the first power supply potential via a third inductor and outputs signal; and an adjustment circuit that outputs a third current corresponding to the first power supply potential or a second power supply potential to the second terminal of the second transistor.

An apparatus and method for calibrating an envelope tracking (ET) lookup table (LUT) are provided. An ET power management apparatus includes a power amplifier configured to amplify a radio frequency (RF) signal from a time-variant input power to a time-variant output power linearly related to the time-variant input power. A calibration circuit is employed to receive a time-variant output power feedback nonlinearly related to the time-variant input power, determine a linear relationship between the time-variant input power and the time-variant output power based on the time-variant output power feedback, and calibrate the ET LUT based on the determined linear relationship. As a result, it is possible to improve accuracy of the ET LUT to thereby improve operating efficiency and linearity of the power amplifier.

A push-pull radio frequency power amplifier includes a coupling feedback circuit, a drive stage circuit and a power output stage circuit, in which the coupling feedback circuit is connected with the drive stage circuit and/or the power output stage circuit; the coupling feedback circuit is configured to generate an alternating voltage at an input end of a first transistor and/or an input end of a push-pull transistor; when the alternating voltage and a voltage at the input end are in a same direction, a positive feedback of an input signal at the input end is achieved; and the first transistor represents a transistor in the drive stage circuit and the push-pull transistor represents a second transistor and a third transistor that form a push-pull structure in the power output stage circuit.

The present disclosure provides a bulk acoustic wave resonance device, a bulk acoustic wave filter device and a radio frequency front end device. The bulk acoustic wave resonance device includes a first layer including a cavity disposed at a first side of the first layer; a first electrode layer disposed in the cavity; a second layer disposed at the first side and disposed on the first electrode layer, and the second layer is a flat layer and covers the first cavity; and a second electrode layer disposed at the first side and disposed on the second layer, and the first electrode layer includes at least two first electrode bars or the second electrode layer includes at least two second electrode bars. The present disclosure can increase the difference between acoustic impedance of a resonance region and a non-resonance region, thereby increasing Q value of the resonance device.

An amplitude modulation-phase modulation compensation circuit includes a detection circuit, a reconfigurable current control voltage source circuit and a phase shifting circuit, in which, the detection circuit is configured to detect the power of an input signal and output a control current according to the power of the input signal when the power of the input signal is greater than a preset power threshold; the reconfigurable current control voltage source circuit is configured to generate a bias voltage according to the control current; the phase shifting circuit is configured to compensate the AM-PM distortion of the radio frequency power amplifier according to the bias voltage. In this way, by the compensation circuit, when the power of the input signal is greater than a preset power threshold, the AM-PM distortion of the radio frequency power amplifier can be compensated according to the power of the input signal.

A peak detector for a power amplifier is provided that includes a threshold voltage detector configured to pulse a detection current in response to an amplified output signal from the amplifier exceeding a peak threshold. A plurality of such peak detectors may be integrated with a corresponding plurality of power amplifiers in a transmitter. Should any peak detector assert an alarm signal or more than a threshold number of alarm signals during a given period, a controller reduces a gain for the plurality of power amplifiers.

A device includes an integrated circuit (IC) die. The IC die includes a silicon germanium (SiGe) substrate, a first RF signal input terminal, a first RF signal output terminal, a first amplification path between the first RF signal input terminal and the first RF signal output terminal, a second RF signal input terminal, a second RF signal output terminal, and a second amplification path between the second RF signal input terminal and the second RF signal output terminal. The device includes a first power transistor die including a first input terminal electrically connected to the first RF signal output terminal and a second power transistor die including a second input terminal electrically connected to the second RF signal output terminal. The first amplification path can include two heterojunction bipolar transistors (HBTs) connected in a cascode configuration and the second amplification path can include two HBTs connected in a cascode configuration.

In some embodiments, a power supply system for a power amplifier can include a voltage converter implemented generate a first voltage at an output node, and an envelope following circuit implemented to generate and combine a second voltage with the first voltage to provide a combined output voltage for the power amplifier. The combined output voltage can have a waveform that follows one or more peaks of an envelope of a radio-frequency signal above the first voltage.

In some embodiments, a power supply system for a power amplifier can include a voltage converter implemented generate a first voltage at an output node, and an envelope following circuit implemented to generate and combine a second voltage with the first voltage to provide a combined output voltage for the power amplifier. The combined output voltage can have a waveform that follows one or more peaks of an envelope of a radio-frequency signal above the first voltage.

Amplifier circuits, radio communication circuits, radio communication devices, and methods provided in this disclosure. The amplifier circuit may include an amplifier configured to amplify an input signal to provide an output signal. The output signal of the amplifier may include a direct current (DC) signal. The amplifier circuit may further include a current source coupled to the amplifier. The current source may be configured to receive an electrical supply. The current source may further be configured to divide the direct current (DC) signal of the output signal based on the electrical supply.