Abstract: Wideband power combiners and splitters are provided herein. In certain embodiments, a power combiner/splitter is implemented with a first coil connecting a first port and a second port, and a second coil connecting a third port and a fourth port. The first coil and the second coil are inductively coupled to one another. For example, the first coil and the second coil can be formed using adjacent conductive layers of a semiconductor chip, an integrated passive device, or a laminate. The power combiner/splitter further includes a fifth port tapping a center of the first coil and a sixth port tapping a center of the second coil. The fifth port and the sixth port serve to connect capacitors and/or other impedance to the center of the coils to thereby provide wideband operation.

Abstract: According to some implementations, a radio-frequency (RF) device includes a communication interface coupled to a serial bus. The RF device also includes a monitoring component coupled to the communication interface, the monitoring component configured to monitor the serial bus for first data transmitted to a first device coupled to the serial bus and configure the RF device based on the first data.

Abstract: Apparatus and methods for quadrature combined Doherty amplifiers are provided herein. In certain embodiments, a separator is used to separate a radio frequency (RF) input signal into a plurality of input signal components that are amplified by a pair of Doherty amplifiers operating in quadrature. Additionally, a combiner is used to combine a plurality of output signal components generated by the pair of Doherty amplifiers, thereby generating an RF output signal exhibiting quadrature balancing.

Abstract: Wideband power combiners and splitters are provided herein. In certain embodiments, a power combiner/splitter is implemented with a first coil connecting a first port and a second port, and a second coil connecting a third port and a fourth port. The first coil and the second coil are inductively coupled to one another. For example, the first coil and the second coil can be formed using adjacent conductive layers of a semiconductor chip, an integrated passive device, or a laminate. The power combiner/splitter further includes a fifth port tapping a center of the first coil and a sixth port tapping a center of the second coil. The fifth port and the sixth port serve to connect capacitors and/or other impedance to the center of the coils to thereby provide wideband operation.

Abstract: Doherty amplifier having envelope control. In some embodiments, an amplifier system can include a Doherty amplifier having a carrier amplifier and a peaking amplifier, with each of the carrier amplifier and the peaking amplifier including a cascode stage with input and output transistors arranged in a cascode configuration. The amplifier system can further include an envelope tracking bias circuit coupled to the Doherty amplifier and configured to provide a bias signal to the output transistor of the cascode stage of the peaking amplifier.

Abstract: Quadrature amplifier having envelope control. In some embodiments, an amplifier system can include a quadrature amplifier having first and second amplifiers configured to amplify first and second signals in quadrature relative to each other, with each of the first and second amplifiers including a cascode stage with input and output transistors arranged in a cascode configuration. The amplifier system can further include an envelope tracking bias circuit coupled to the quadrature amplifier and configured to provide a bias signal to the output transistor of the cascode stage of at least one of the first and second amplifiers.

Abstract: Amplifiers for radio-frequency applications. In some embodiments, a power amplifier die can include a semiconductor substrate and a plurality of narrow band power amplifiers implemented on the semiconductor substrate. Each narrow band power amplifier can be configured to operate with a high voltage in an average power tracking mode and be capable of being coupled to an output filter associated with a respective individual frequency band. Each narrow band power amplifier can be sized smaller than a wide band power amplifier configured to operate with more than one of the frequency bands associated with the plurality of narrow band power amplifiers.

Abstract: A high-voltage power amplification system can include a supply circuit configured to provide a high supply voltage in an average power tracking mode. The power amplification system can further include a power amplifier configured to operate with the high supply voltage and provide an impedance that substantially matches an impedance of a component coupled to an output of the power amplifier. The power amplification system can further include a signal path configured to route an amplified signal from the output of the power amplifier to the component, with the output path being substantially free of an output matching network.

Abstract: Power amplifiers having reduced loss. In some embodiments, a power amplification system can include a plurality of power amplifiers, with each power amplifier being configured to receive and amplify a signal in a frequency band. The power amplification system can further include an output filter coupled to each of the power amplifiers by a separate output path such that the power amplification system is substantially free of a band selection switch between the plurality of power amplifiers and their corresponding output filters. Each power amplifier can be further configured to operate with a high-voltage supply to provide an impedance similar to an impedance of the corresponding output filter.

Abstract: One aspect of this disclosure is a power amplifier module that includes a power amplifier on a substrate and a semiconductor resistor on the substrate. The power amplifier includes a bipolar transistor having a collector, a base, and an emitter. The collector has a doping concentration of at least 3×1016 cm?3 at an interface with the base. The collector also has at least a first grading in which doping concentration increases away from the base. The semiconductor resistor includes a resistive layer that that includes the same material as a layer of the bipolar transistor. Other embodiments of the module are provided along with related methods and components thereof.

Abstract: Doherty power amplifier having high supply voltage. In some embodiments, a power amplification system can include a supply system configured to provide a high-voltage supply signal, and a Doherty power amplifier having an input splitter configured to receive and split a signal into a carrier amplifier and a peaking amplifier. The Doherty power amplifier can further include a combiner configured to combine amplified signals from the carrier and peaking amplifiers to provide an output signal. The Doherty power amplifier can be configured to receive the high-voltage supply signal for operation of the carrier and peaking amplifiers. The power amplification system can further include an output path configured to couple the combiner to a filter. The Doherty power amplifier can have an impedance substantially the same as an impedance of the filter when operated with the high-voltage supply signal.

Abstract: Wideband power combiners and splitters are provided herein. In certain embodiments, a power combiner/splitter is implemented with a first coil connecting a first port and a second port, and a second coil connecting a third port and a fourth port. The first coil and the second coil are inductively coupled to one another. For example, the first coil and the second coil can be formed using adjacent conductive layers of a semiconductor chip, an integrated passive device, or a laminate. The power combiner/splitter further includes a fifth port tapping a center of the first coil and a sixth port tapping a center of the second coil. The fifth port and the sixth port serve to connect capacitors and/or other impedance to the center of the coils to thereby provide wideband operation.

Abstract: A power amplification system with shared common base biasing is disclosed. A method for power amplification at a controller of a power amplification system comprising a plurality of cascode amplifier sections can include receiving a band select signal indicative of one or more frequency bands of a radio-frequency input signal to be amplified and transmitted. The method may further include biasing a common base stage of each of the plurality of cascode amplifier sections, and biasing a common emitter stage of a subset of the plurality of cascode amplifier sections.

Abstract: The present disclosure relates to devices and methods for detecting and preventing occurrence of a saturation state in a power amplifier. A power amplifier module can include a power amplifier including a cascode transistor pair. The cascode transistor pair can include a first transistor and a second transistor. The power amplifier module can include a current comparator configured to compare a first base current of the first transistor and a second base current of the second transistor to obtain a comparison value. The power amplifier module can include a saturation controller configured to supply a reference signal to an impedance matching network based on the comparison value. The impedance matching network can be configured to modify a load impedance of a load line in electrical communication with the power amplifier based at least in part on the reference signal.

Abstract: Power amplification system with variable supply voltage. A power amplification system can include a power amplifier and a boost converter configured to provide a supply voltage to the power amplifier. The power amplification system can include a control system configured to provide a boost converter control signal to the boost converter to adjust the supply voltage based on a parameter associated with the power amplifier.

Abstract: In some embodiments, a power amplification system can comprise a current source, an input switch configured to alternatively feed current from the current source to a high-power circuit path and a low-power circuit path, and a band switch including a switch arm for switching between a plurality of bands. Each of the high-power circuit path and the low-power circuit path can be connected to the switch arm.

Abstract: 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.

Abstract: According to some implementations, a power amplifier (PA) includes a common emitter configured to receive a radio-frequency (RF) signal. The PA also includes a carrier amplifier coupled to the common emitter to form a carrier cascode configuration, a collector of the carrier amplifier provided with a first supply voltage. The PA further includes a peaking amplifier coupled to the common emitter to form a peaking cascode configuration, a collector of the peaking amplifier provided with a second supply voltage greater than the first supply voltage.

Abstract: Systems and methods including variable power amplifier bias impedance are disclosed. In one aspect, there is provided a power amplifier system including a bias circuit configured to receive a bias voltage and generate a bias signal and a power amplifier stage configured to receive an input radio frequency (RF) signal and generate an output RF signal. The power amplifier system may also include a bias impedance component operatively coupled between the bias circuit and the power amplifier stage. The bias impedance is component configured to receive a control signal and adjust an impedance value of the bias impedance component in response to the control signal.

Abstract: Apparatus and methods for quadrature combined Doherty amplifiers are provided herein. In certain embodiments, a separator is used to separate a radio frequency (RF) input signal into a plurality of input signal components that are amplified by a pair of Doherty amplifiers operating in quadrature. Additionally, a combiner is used to combine a plurality of output signal components generated by the pair of Doherty amplifiers, thereby generating an RF output signal exhibiting quadrature balancing.