An apparatus includes: a transistor including an input terminal for an input signal and an output terminal for an output signal; a matching circuit configured to match a load impedance regarding a fundamental harmonic of at least one of the input signal and the output signal to an impedance of the transistor and include a first conductive film being laminated over the transistor and coupled to at least one of the input terminal and the output terminal; and a processing circuit configured to adjust an impedance regarding a harmonic of at least one of the input signal and the output signal and include a second conductive film being laminated over the first conductive film and coupled to at least one of the input terminal and the output terminal through a via which penetrates through a dielectric layer sandwiched between the first conductive film and the second conductive film.

A transistor stack can include a combination of floating and body tied devices. Improved performance of the RF amplifier can be obtained by using a single body tied device as the input transistor of the stack, or as the output transistor of the stack, while other transistors of the stack are floating transistors. Transient response of the RF amplifier can be improved by using all body tied devices in the stack.

A transistor stack can include a combination of floating and body tied devices. Improved performance of the RF amplifier can be obtained by using a single body tied device as the input transistor of the stack, or as the output transistor of the stack, while other transistors of the stack are floating transistors. Transient response of the RF amplifier can be improved by using all body tied devices in the stack.

Apparatus and methods for power amplifiers with positive envelope feedback are provided herein. In certain implementations, a power amplifier system includes a power amplification stage that amplifies a radio frequency signal, at least one envelope detector that generates one or more detection signals indicating an output signal envelope of the power amplification stage, and a wideband feedback circuit that provides positive envelope feedback to a bias of the power amplification stage based on the one or more detection signals. The power amplifier system further includes a supply modulator that controls a voltage level of a supply voltage of the power amplification stage based on the one or more detection signals such that the supply voltage is modulated with the output signal envelope through positive envelope feedback.

Apparatus and methods for power amplifiers with positive envelope feedback are provided herein. In certain implementations, a power amplifier system includes a power amplification stage that amplifies a radio frequency signal, at least one envelope detector that generates one or more detection signals indicating an output signal envelope of the power amplification stage, and a wideband feedback circuit that provides positive envelope feedback to a bias of the power amplification stage based on the one or more detection signals. The power amplifier system further includes a supply modulator that controls a voltage level of a supply voltage of the power amplification stage based on the one or more detection signals such that the supply voltage is modulated with the output signal envelope through positive envelope feedback.

The embodiments described herein provide radio frequency (RF) amplifiers, and in some embodiments provide amplifiers that can be used in high power RF applications. Specifically, the amplifiers described herein may be implemented with multiple resonant circuits to provide class F and inverse class F amplifiers and methods of operation. In general, the resonant circuits are implemented inside a device package with a transistor die to provide high efficiency amplification for a variety of applications.

The embodiments described herein provide radio frequency (RF) amplifiers, and in some embodiments provide amplifiers that can be used in high power RF applications. Specifically, the amplifiers described herein may be implemented with multiple resonant circuits to provide class F and inverse class F amplifiers and methods of operation. In general, the resonant circuits are implemented inside a device package with a transistor die to provide high efficiency amplification for a variety of applications.

The embodiments described herein provide radio frequency (RF) amplifiers, and in some embodiments provide amplifiers that can be used in high power RF applications. Specifically, the amplifiers described herein may be implemented with multiple resonant circuits to provide class F and inverse class F amplifiers and methods of operation. In general, the resonant circuits are implemented inside a device package with a transistor die to provide high efficiency amplification for a variety of applications.

The embodiments described herein provide radio frequency (RF) amplifiers, and in some embodiments provide amplifiers that can be used in high power RF applications. Specifically, the amplifiers described herein may be implemented with multiple resonant circuits to provide class F and inverse class F amplifiers and methods of operation. In general, the resonant circuits are implemented inside a device package with a transistor die to provide high efficiency amplification for a variety of applications.

An amplifier circuit includes an input port, an output port, and a reference potential port, an RF amplifier device having an input terminal electrically coupled to the input port, an output terminal electrically coupled to the output port, and a reference potential terminal electrically coupled to the reference potential port. An impedance matching network is electrically connected to the output terminal, the reference potential port, and the output port. The impedance matching network includes a reactive efficiency optimization circuit that forms a parallel resonant circuit with a characteristic output impedance of the peaking amplifier at a center frequency of the fundamental frequency range. The impedance matching network includes a reactive frequency selective circuit that negates a phase shift of the RF signal in phase at the center frequency and exhibits a linear transfer characteristic in a baseband frequency range.