Example embodiments relate to push-pull class E amplifiers. One example push-pull class E amplifier includes an input configured for receiving a signal to be amplified. The push-pull class E amplifier also includes an output configured for outputting the signal after amplification. Additionally, the push-pull class E amplifier includes a printed circuit board having a first dielectric layer and a second dielectric layer. Further, the push-pull class E amplifier includes a first amplifying unit and a second amplifying unit. Yet further, the push-pull class E amplifier includes a balun, a capacitive unit, a first line segment, a second line segment, a third line segment, and a fourth line segment. The first line segment and the second line segment are arranged on the first dielectric layer. A combined length of the third line segment and the fourth line segment corresponds to a quarter wavelength of an operational frequency of the amplifier.

A power amplifying circuit includes a single-ended amplifier, a differential amplifier, a first balun transformer, a second balun transformer, and a first switching circuit. The single-ended amplifier operates in a first mode and a second mode different from the first mode. The differential amplifier operates in the second mode. The first balun transformer converts an unbalanced output signal from the single-ended amplifier into a differential signal and outputs the differential signal to the differential amplifier. The second balun transformer converts a balanced output signal from the differential amplifier into an unbalanced output signal. The first switching circuit outputs the unbalanced output signal from the single-ended amplifier in the first mode and outputs the unbalanced output signal from the second balun transformer in the second mode.

A wide band matching network for power amplifier impedance matching, the wide band matching network comprising: a power amplifier transistor connected to an output network; the output network including: a series capacitor; an on-chip transformer connected to the capacitor in series, wherein the transformer and the capacitor act as a second order filter; and a port connected to the capacitor and a receiver switch.

MJC/ll

A power amplifier circuit includes a first amplifier that operates in accordance with a first voltage supplied from a voltage supply source, amplifies a first signal, and outputs an amplification signal, a bias transistor that includes a base or a gate to which a bias control current is supplied and an emitter or a source supplying a bias to the first amplifier through a first resistor element, and a protection circuit that causes part of the bias control current to flow to a ground on the basis of the amplification signal and a second signal based on the first voltage.

An electronic circuit includes a differential output circuit that produces a differential output signal at a differential output. A primary winding of a balun has a first balun terminal coupled to a first differential output terminal, and a second balun terminal coupled to a second differential output terminal. A configurable harmonic reduction circuit includes first and second configurable shunt capacitance circuits coupled between the first differential output terminal or the second differential output terminal, respectively, and a ground reference node. A control circuit receives tuning data associated with a calibrated tuning state. The tuning data indicates a first and second calibrated capacitance values, which are unequal, for the first and second configurable shunt capacitance circuits, respectively. The control circuit controls the first configurable shunt capacitance circuit to have the first calibrated capacitance value, and controls the second configurable shunt capacitance circuit to have the second calibrated capacitance value.

Apparatus and methods for radio frequency (RF) amplification are disclosed. In certain embodiments, an RF amplifier includes an output node configured to output an RF output signal, a main amplifier stage including a differential output, a first differential balun combiner configured to provide a first single-ended RF signal to the output node based on combining a first differential RF signal from the differential output of the main amplifier stage, an auxiliary amplifier stage including a differential output, a transformer component, and a second differential balun combiner configured to generate a second single-ended RF signal based on combining a second differential RF signal from the differential output of the auxiliary amplifier stage. The second differential balun combiner provides the second single-ended RF signal to the output node through the transformer component.

A differential amplifying apparatus includes an input matching circuit serving as an input balun to which a signal inputted to an input terminal is input, an output matching circuit serving as an output balun that outputs a signal to an output terminal, first and second amplifiers provided in parallel between the input balun and the output balun and configured to output a differential signal, a diode provided between a reference potential and a path between the input balun and the first amplifier, a second diode provided between a reference potential and a path between the input balun and the second amplifier, and a bias circuit that applies a bias to the first diode and the second diode, in which a cathode of the first diode and a cathode of the second diode are connected to the reference potential side.

A power amplification system is provided comprising: a power amplifier circuit, the power amplifier circuit including a plurality of transistors; and a frequency response compensation circuit for providing a plurality of values of capacitance. The frequency response compensation circuit having at least one tuning capacitor. Each of the at least one tuning capacitors is coupled to a tuning switch for regulating the current path to and/or from the corresponding capacitor to control the value of the capacitance provided by the frequency response compensation circuit. The frequency response compensation circuit is coupled to at least two of the transistors of the power amplifier circuit. The frequency response compensation circuit is configured to reduce variation over frequency of a load impedance of the power amplification system. A wireless device comprising such a power amplification system is also provided. A wireless module comprising such a power amplification system is also provided.

A power amplification system is provided comprising: a power amplifier circuit; an output power control circuit for providing a plurality of values of capacitance, and a balun coupled to the power amplifier circuit and to the output power control circuit. The output power control circuit includes at least one load control capacitor. Each of the at least one load control capacitors is coupled to a load control switch for regulating the current path to and/or from the corresponding capacitor to control the value of the capacitance provided by the output power control circuit. A wireless device comprising such a power amplification system is also provided. A wireless module comprising such a power amplification system is also provided.

A mobile device can have a transceiver configured to generate a radio frequency signal and a power management system with envelope tracking. The device can also have a power amplifier system having a driver transistor coupled to a radio frequency signal input, a transformer balun having a main primary coil connected between the driver transistor and a voltage supply node of the power amplifier system, a secondary coil magnetically coupled to the main primary coil and an additional primary coil configured to generate a feedback signal related to a signal of the main primary coil. The power amplifier system can also have a push-pull amplifier with a first transistor having a base connected to a first end of the secondary coil and a second transistor having a base connected to a second end of the secondary coil. Accordingly, push-pull stage neutralization can deploy two transistors cross-connected to opposite ends of an output coil in a transformer balun.