Radio frequency (RF) amplifiers with capacitance neutralization are provided. In certain embodiments, an RF amplifier includes an RF input terminal, an RF output terminal, a gain transistor including a control terminal that receives an RF signal from the RF input terminal, a cascode transistor connected in series with the gain transistor and that provides an amplified RF signal to the RF output terminal, and a neutralization capacitor connected in parallel with the cascode transistor.

One example includes a device that is comprised of a pre-power amplifier, a power amplifier, a signal path, and a dynamic bias circuit. The pre-power amplifier amplifies an input signal and outputs a first amplified signal. The power amplifier receives the first amplified signal and amplifies the first amplified signal based on a dynamic bias signal to produce a second amplified signal at an output thereof. The signal path is coupled between an output of the pre-power amplifier and an input of the power amplifier. The dynamic bias circuit monitors the first amplified signal, generates the dynamic bias signal, and outputs the dynamic bias into the signal path.

One example includes a device that is comprised of a pre-power amplifier, a power amplifier, a signal path, and a dynamic bias circuit. The pre-power amplifier amplifies an input signal and outputs a first amplified signal. The power amplifier receives the first amplified signal and amplifies the first amplified signal based on a dynamic bias signal to produce a second amplified signal at an output thereof. The signal path is coupled between an output of the pre-power amplifier and an input of the power amplifier. The dynamic bias circuit monitors the first amplified signal, generates the dynamic bias signal, and outputs the dynamic bias into the signal path.

RF transistor amplifiers include a Group III nitride-based RF transistor amplifier die that includes a semiconductor layer structure, a conductive source via that is connected to a source region of the Group III nitride-based RF transistor amplifier die, the conductive source via extending through the semiconductor layer structure, and an additional conductive via that extends through the semiconductor layer structure. A first end of the additional conductive via is connected to a first external circuit and a second end of the additional conductive via that is opposite the first end is connected to a first matching circuit.

RF transistor amplifiers include a Group III nitride-based RF transistor amplifier die that includes a semiconductor layer structure, a conductive source via that is connected to a source region of the Group III nitride-based RF transistor amplifier die, the conductive source via extending through the semiconductor layer structure, and an additional conductive via that extends through the semiconductor layer structure. A first end of the additional conductive via is connected to a first external circuit and a second end of the additional conductive via that is opposite the first end is connected to a first matching circuit.

Disclosed are systems configured to deliver wireless charging power to electronic devices and methods for delivering wireless charging power. In some implementations, a system can include a programmable radio-frequency generator capable of generating a beam of electromagnetic pulsed radiation and plurality of solid-state amplifiers to amplify the beam of electromagnetic pulsed radiation. The amplified beam of electromagnetic pulsed radiation can be configured to wirelessly charge electronic devices at distances greater than about 100 meters.

Methods and systems for optimizing amplifier operations are described. The described methods and systems particularly describe a feed-forward control circuit that may also be used as a feed-back control circuit in certain applications. The feed-forward control circuit provides a control signal that may be used to configure an amplifier in a variety of ways.

Methods and systems for optimizing amplifier operations are described. The described methods and systems particularly describe a feed-forward control circuit that may also be used as a feed-back control circuit in certain applications. The feed-forward control circuit provides a control signal that may be used to configure an amplifier in a variety of ways.

A low-noise amplifier in a receiver supporting a beam forming function may selectively change a phase shift for beam steering. The low-noise amplifier may include first and second transistors and a variable capacitance circuit connected to a gate of the second transistor. The variable capacitance circuit may selectively change capacitance thereof based on a capacitance control signal applied thereto according to beam-forming information, where the changed capacitance correspondingly causes a phase change in an output signal of the low-noise amplifier. A similar scheme may be employed for amplifiers in transmit signal paths to steer a transmit beam.

A low-noise amplifier in a receiver supporting a beam forming function may selectively change a phase shift for beam steering. The low-noise amplifier may include first and second transistors and a variable capacitance circuit connected to a gate of the second transistor. The variable capacitance circuit may selectively change capacitance thereof based on a capacitance control signal applied thereto according to beam-forming information, where the changed capacitance correspondingly causes a phase change in an output signal of the low-noise amplifier. A similar scheme may be employed for amplifiers in transmit signal paths to steer a transmit beam.