Embodiments of circuits for use with an amplifier that includes multiple amplifier paths include a first circuit and a second circuit in parallel with the first circuit. The first circuit includes a first input coupled to a first power divider output, a first output coupled to a first amplifier path of the multiple amplifier paths, and a first adjustable phase shifter and a first attenuator series coupled between the first input and the first output. The second circuit includes a second input coupled to a second power divider output, a second output coupled to a second amplifier path of the multiple amplifier paths, and a second adjustable phase shifter coupled between the second input and the second output.