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.

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.