Abstract: According to at least one aspect of the disclosure, a front-end module is provided comprising an input configured to receive a radio-frequency signal, an output configured to be coupled to an antenna, a balun coupled to the output, one or more power amplifiers coupled to the input, and an inverter coupled between the one or more power amplifiers and the balun, the inverter being configured to provide output impedance matching to the one or more power amplifiers.

Abstract: Apparatus and methods for power amplifier systems with balun and shunt capacitor are disclosed. In certain embodiments, a front-end system includes a shunt capacitor, a balun having an input side and an output side, and power amplifier stages that operate in parallel with one another to amplify a radio frequency input signal. The power amplifier stages include a first power amplifier stage having a first output coupled to the shunt capacitor and to a first input terminal on the input side of the balun, and a second power amplifier stage having a second output coupled to a second input terminal on the input side of the balun.

Abstract: Apparatus and methods for power amplifiers with broadband matching networks are disclosed. In certain embodiments, a mobile device includes a transceiver that generates a radio frequency input signal, and a front-end system including a compound semiconductor die and a silicon switch die. The compound semiconductor die includes a power amplifier including one or more power amplifier stages that amplify the radio frequency input signal to generate a radio frequency output signal. The silicon switch die includes a band selection switch that receives the radio frequency output signal. The compound semiconductor die and the silicon switch die each include at least one controllable impedance for providing a bandwidth adjustment to the power amplifier.

Abstract: Power amplification system is disclosed. A power amplification system can include a Class-E push-pull amplifier including a transformer balun. The power amplification can further include a reactance compensation circuit coupled to the transformer balun. In some embodiments, the reactance compensation circuit is configured to reduce variation over frequency of a fundamental load impedance of the power amplification system.

Abstract: In some embodiments, a power amplification system can include a common base amplifier configured to amplify an input signal received at an input node to generate an intermediate signal at an intermediate node. The power amplification system can further include a power amplifier configured to amplify the intermediate signal received at the intermediate node to generate an output signal at an output node.

Abstract: Power amplification system is disclosed. A power amplification system can include a Class-E push-pull amplifier including a transformer balun. The power amplification can further include a reactance compensation circuit coupled to the transformer balun. In some embodiments, the reactance compensation circuit is configured to reduce variation over frequency of a fundamental load impedance of the power amplification system.

Abstract: Power amplification system is disclosed. A power amplification system can include a Class-E push-pull amplifier including a transformer balun. The power amplification can further include a reactance compensation circuit coupled to the transformer balun. In some embodiments, the reactance compensation circuit is configured to reduce variation over frequency of a fundamental load impedance of the power amplification system.

Abstract: In some embodiments, a power amplification system can include a common base amplifier configured to amplify an input signal received at an input node to generate an intermediate signal at an intermediate node. The power amplification system can further include a power amplifier configured to amplify the intermediate signal received at the intermediate node to generate an output signal at an output node.

Abstract: Power amplification system is disclosed. A power amplification system can include a Class-E push-pull amplifier including a transformer balun. The power amplification can further include a reactance compensation circuit coupled to the transformer balun. In some embodiments, the reactance compensation circuit is configured to reduce variation over frequency of a fundamental load impedance of the power amplification system.

Abstract: Power amplification system with common base pre-amplifier. A power amplification system can include a common base amplifier configured to amplify an input radio-frequency (RF) signal received at an input node to generate an intermediate RF signal at an intermediate node. The power amplification system can further include a power amplifier configured to amplify the intermediate RF signal received at the intermediate node to generate an output RF signal at an output node.

Abstract: Power amplification system is disclosed. A power amplification system can include a Class-E push-pull amplifier including a transformer balun. The power amplification can further include a reactance compensation circuit coupled to the transformer balun. In some embodiments, the reactance compensation circuit is configured to reduce variation over frequency of a fundamental load impedance of the power amplification system.

Abstract: Power amplification system is disclosed. A power amplification system can include a Class-E push-pull amplifier including a transformer balun. The power amplification can further include a reactance compensation circuit coupled to the transformer balun. In some embodiments, the reactance compensation circuit is configured to reduce variation over frequency of a fundamental load impedance of the power amplification system.

Abstract: Power amplification system with common base pre-amplifier. A power amplification system can include a common base amplifier configured to amplify an input radio-frequency (RF) signal received at an input node to generate an intermediate RF signal at an intermediate node. The power amplification system can further include a power amplifier configured to amplify the intermediate RF signal received at the intermediate node to generate an output RF signal at an output node.