Power amplification system with adjustable common base bias. A power amplification system can include a cascode amplifier coupled to a radio-frequency input signal and coupled to a radio-frequency output. The power amplification system can further include a biasing component configured to apply one or more biasing signals to the cascode amplifier, the biasing component including a bias controller and one or more bias components. Each respective bias component may be coupled to a respective bias transistor.

A method of a wireless transmitter is disclosed. The method is for mitigation of distortion caused by non-linear hardware components of the transmitter, wherein mitigation of distortion comprises mitigating at least one intermodulation component, wherein the transmitter is configured to process an input signal having an input signal spectrum, and wherein the transmitter comprises two or more signal branches, each signal branch comprising a respective non-linear hardware component. The method comprises modifying the input signal for a first one of the signal branches by applying a first phase shift to a first part of the input signal spectrum, wherein the first phase shift has a first sign and a first absolute value, and applying a second phase shift to a second part of the input signal spectrum. The second phase shift has a second sign which is opposite to the first sign, and a second absolute value which is equal to the first absolute value. The first and second parts are non-overlapping. The method also comprises modifying the input signal for a second one of the signal branches by applying the first phase shift to the second part of the input signal spectrum, and applying the second phase shift to the first part of the input signal spectrum. The method further comprises feeding the modified input signals to respective ones of the signal branches. Corresponding apparatus, wireless transmitter, communication device, and computer program product are also disclosed.

A matching circuit includes first and second ports, an autotransformer, and first and second capacitors. The autotransformer includes a first terminal coupled to a first port, a second terminal coupled to a second port, and a common terminal coupled to a reference potential, and includes a series parasitic inductor and a parallel parasitic inductor. The first capacitor is coupled in shunt to the second terminal, and defines a low pass filter together with the series parasitic inductor. The second capacitor is coupled in series between the first port and the first terminal, and defines a high pass filter together with the parallel parasitic inductor.

An apparatus is provided that includes circuitry for decomposing an input signal to multiple substantially constant-envelope components and an outphasing path for each substantially constant-envelope component. The apparatus also includes a modulator for discrete phase control in each outphasing path, an amplifier in each outphasing path and a combiner for combining output signals from the outphasing paths. A system and method are also provided.

Technologies directed to cable-loss compensation are described. An apparatus includes a triplexer, a front-end module (FEM) circuit, and a control circuit. The triplexer is coupled to a radio frequency (RF) cable. The triplexer receives a first RF signal and a DC power signal from a device via the RF cable and sends a detection signal being indicative of a transmit power level of the first RF signal to the device via the RF cable. The transmit power level includes an insertion loss of the RF cable. The FEM circuit is coupled to the triplexer and includes a power amplifier (PA). The control circuit is coupled to the triplexer and measures the transmit power level of the first RF signal and converts the first RF signal into the detection signal. The control circuit sends the detection signal back to the device via the RF cable and enables the PA.

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.