Radio frequency power amplifier

A radio frequency power amplifier comprising:

• an input terminal for receiving an input signal having an input power and an output terminal for outputting an output signal having an output power larger than the input power,
• a main amplifier stage having a main input terminal for receiving a main input signal and a main output terminal for providing a main output signal, the main input terminal electrically coupled to the input terminal;
• a peak amplifier stage having a peak input terminal for receiving a peak input signal and a peak output terminal for providing a peak output signal, the peak input terminal electrically coupled to the input terminal,
• an output power combiner for combining the main output signal and the peak output signal into the output signal, comprising a first combiner terminal electrically coupled to the main output terminal for receiving the main output signal from the main output terminal and a second combiner terminal electrically coupled to the peak output terminal for receiving the peak output signal from the peak output terminal, the power combiner further comprising:
• a first transition structure extending from the first combiner terminal in a first direction to a first end,
• a second transition structure extending from the second combiner terminal in the first direction to a second end,
• a first electrical conductor for providing a phase shift between the main output signal and the peak output signal, the first electrical conductor being arranged between the first end and the second end, and
• a second electrical conductor arranged between the second combiner terminal and the output terminal for providing the output signal to the output terminal;
• the first electrical conductor extending in a second direction perpendicular to the first direction, the second electrical conductor extending in the first direction.