Doherty Power Amplifier Network

A network comprising:

• an output matching network coupled to an amplifier transistor characterized by at least one amplifier transistor output impedance, the output matching network including an in-phase signal path disposed in parallel with a quadrature signal path, the output matching network being configured to transform the at least one amplifier transistor output impedance to an output matching network impedance, the output matching network impedance being intermediate the at least one amplifier transistor output impedance and a load impedance;
• and
• a combiner network coupled to the output matching network, the combiner network including a first quarter wavelength transmission line coupled between the in-phase signal path and a combiner node, the first quarter wavelength transmission line being configured to substantially eliminate a phase delay between an in-phase signal and a quadrature signal, the combiner network further including a bandwidth enhancement element coupled to the quadrature signal path at the combiner node, and an impedance transformation element coupled between the combiner node and a load, the impedance transformation element being configured to substantially transform a combined output matching network impedance at the combiner node to the load impedance.