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 power amplifier module includes an output-stage amplifier, a driver-stage amplifier, an input switch, an output switch, an input matching circuit, an inter-stage matching circuit, an output matching circuit, and a control circuit. The input switch selectively connects one of a plurality of input signal paths to an input terminal of the driver-stage amplifier. The output switch selectively connects one of a plurality of output signal paths to an output terminal of the output-stage amplifier. The control circuit controls operations of the driver-stage amplifier and the output-stage amplifier. The input switch, the output switch, and the control circuit are integrated into an IC chip. The control circuit is disposed between the input switch and the output switch.

An amplifier device includes an input terminal, an output terminal, a first transistor having a control terminal and first and second current-carrying terminals, and a class-J circuit coupled between the second current-carrying terminal of the first transistor and the output terminal and configured to harmonically terminate the first transistor. The class-J circuit may include a first resonator, characterized by a first resonant frequency substantially equal to a second harmonic frequency. The first resonator may be coupled between the second current-carrying terminal and a voltage reference. A shunt inductor that is distinct from the first resonator may be coupled between the second current-carrying terminal and the voltage reference.

A power amplifier circuit includes a lower transistor having a first terminal, a second terminal connected to ground, and a third terminal, wherein a first power supply voltage is supplied to the first terminal, and an input signal is supplied to the third terminal; a first capacitor; an upper transistor having a first terminal, a second terminal connected to the first terminal of the lower transistor via the first capacitor, and a third terminal, wherein a second power supply voltage is supplied to the first terminal, an amplified signal is outputted to an output terminal from the first terminal, and a driving voltage is supplied to the third terminal; a first inductor that connects the second terminal of the upper transistor to ground; a voltage regulator circuit; and at least one termination circuit that short-circuits an even-order harmonic or odd-order harmonic of the amplified signal to ground potential.

Exemplary impedance matching circuit for an amplifier device comprises a broadband impedance transformer configured to transform, over a fundamental frequency range, an impedance associated with an input port or an output port of the impedance matching circuit; and to transmit RF signals having a fundamental frequency within the fundamental frequency range. The impedance matching circuit also includes a phase shifter circuit configured to transmit, with substantially matched impedance, the RF signals having a fundamental frequency within the fundamental frequency range, and to phase-shift higher-order harmonics of the RF signals. The impedance matching circuit also includes a high-pass impedance transformer configured to match an impedance of the RF signals having a fundamental frequency within the fundamental frequency range; and to transmit, with low reflection, second-order harmonics of the RF signals. Exemplary embodiments also include amplifier circuits comprising an RF amplifier and embodiments of the impedance matching circuit.

Exemplary impedance matching circuit for an amplifier device comprises a broadband impedance transformer configured to transform, over a fundamental frequency range, an impedance associated with an input port or an output port of the impedance matching circuit; and to transmit RF signals having a fundamental frequency within the fundamental frequency range. The impedance matching circuit also includes a phase shifter circuit configured to transmit, with substantially matched impedance, the RF signals having a fundamental frequency within the fundamental frequency range, and to phase-shift higher-order harmonics of the RF signals. The impedance matching circuit also includes a high-pass impedance transformer configured to match an impedance of the RF signals having a fundamental frequency within the fundamental frequency range; and to transmit, with low reflection, second-order harmonics of the RF signals. Exemplary embodiments also include amplifier circuits comprising an RF amplifier and embodiments of the impedance matching circuit.

A power amplifying device includes a first amplification circuit amplifying a first signal having a first frequency component and a second frequency component; a second amplification circuit amplifying a second signal received through an output node of the first amplification circuit; a filter circuit connected between a ground node of the first amplification circuit and a common ground to pass the first and second frequency components to the common ground through the ground node; and an inverting circuit that phase-inverts a signal including second harmonic components of the first and second frequency components that are received through the ground node of the first amplification circuit and provide the phase inverted signal to the output node of the first amplification circuit.

Radio-frequency front-end circuitry includes an output terminal, a receive amplifier controllably coupled to the output terminal, at least one transmit amplifier controllably inductively coupled to the output terminal, and at least one impedance element controllably coupled between ground and one of the at least one transmit amplifier to reduce degradation of output of the radio-frequency front-end circuitry when the at least one transmit amplifier is not in use. In differential signaling, there is an impedance element between ground and each pole of the differential signal. A second transmit amplifier may generate second transmit signals and harmonics of the second transmit signals, and the second transmit amplifier may be switchably connected to the output of a first transmit amplifier so that output of the second transmit amplifier is filtered by the one of the first transmit amplifier. The transmit amplifiers may include a WiFi power amplifier and a BLUETOOTH power amplifier.

Radio-frequency front-end circuitry includes an output terminal, a receive amplifier controllably coupled to the output terminal, at least one transmit amplifier controllably inductively coupled to the output terminal, and at least one impedance element controllably coupled between ground and one of the at least one transmit amplifier to reduce degradation of output of the radio-frequency front-end circuitry when the at least one transmit amplifier is not in use. In differential signaling, there is an impedance element between ground and each pole of the differential signal. A second transmit amplifier may generate second transmit signals and harmonics of the second transmit signals, and the second transmit amplifier may be switchably connected to the output of a first transmit amplifier so that output of the second transmit amplifier is filtered by the one of the first transmit amplifier. The transmit amplifiers may include a WiFi power amplifier and a BLUETOOTH power amplifier.

A first stabilizing circuit (7a) is disposed between a first transistor (5a) and a first output matching circuit (10a) in a first stage. A second stabilizing circuit (7b) is disposed between a second transistor (5b) and a second output matching circuit (10b) in a second stage. The first stabilizing circuit (7a) includes a first band-pass filter and a first resistor (103a) connected in parallel. The first band-pass filter allows a signal of a frequency f1 lower than a central frequency fc of the operation frequencies as an amplifier to pass through. The second stabilizing circuit (7b) includes a second band-pass filter and a second resistor (103b) connected in parallel. The second band-pass filter allows a signal of a frequency f2 higher than the central frequency fc to pass through.