A four-way Doherty amplifier, comprising: an input terminal for receiving a signal to be amplified by the four-way Doherty amplifier; a main amplifier having a main input and a main output; a first peak amplifier having a first input and a first output; a second peak amplifier having a second input and a second output; a third peak amplifier having a third input and a third output; an input distribution network for distributing the signal received at the input terminal to the main amplifier, the first peak amplifier, the second peak amplifier, and the third peak amplifier; and a Doherty combiner for combining, at a first combining node, signals received from the main amplifier, the first peak amplifier, the second peak amplifier, and the third peak amplifier, said Doherty combiner comprising: a second branch between the first combining node and a second combining node and comprising a second impedance inverter (Z 02), wherein the third output is connected to the first combining node via a first branch; a third branch between the second combining node and the main output and comprising a third impedance inverter (Z 03); a fourth branch between the second combining node and a third combining node and comprising a fourth impedance inverter (Z 04), wherein the second output is connected to the third combining node via a sixth branch; and a fifth branch between the first output and the third combining node and comprising a fifth impedance inverter (Z 05); and characterised by a further impedance inverter (Z OUT) connected between the first combining node and an output terminal; wherein the maximum power capacities of the main amplifier, the first peak amplifier, the second peak amplifier, and the third peak amplifier are substantially identical, wherein a supply voltage supplied to the main amplifier, the first peak amplifier, the second peak amplifier, and the third peak amplifier is substantially identical, and wherein the first, second, and third peak amplifiers are configured to turn-on at substantially the same power level of the signal inputted to the Doherty amplifier. an input terminal for receiving a signal to be amplified by the four-way Doherty amplifier; a main amplifier having a main input and a main output; a first peak amplifier having a first input and a first output; a second peak amplifier having a second input and a second output; a third peak amplifier having a third input and a third output; an input distribution network for distributing the signal received at the input terminal to the main amplifier, the first peak amplifier, the second peak amplifier, and the third peak amplifier; and a Doherty combiner for combining, at a first combining node, signals received from the main amplifier, the first peak amplifier, the second peak amplifier, and the third peak amplifier, said Doherty combiner comprising: a second branch between the first combining node and a second combining node and comprising a second impedance inverter (Z 02), wherein the third output is connected to the first combining node via a first branch; a third branch between the second combining node and the main output and comprising a third impedance inverter (Z 03); a fourth branch between the second combining node and a third combining node and comprising a fourth impedance inverter (Z 04), wherein the second output is connected to the third combining node via a sixth branch; and a fifth branch between the first output and the third combining node and comprising a fifth impedance inverter (Z 05); and characterised by a further impedance inverter (Z OUT) connected between the first combining node and an output terminal; a second branch between the first combining node and a second combining node and comprising a second impedance inverter (Z 02), wherein the third output is connected to the first combining node via a first branch; a third branch between the second combining node and the main output and comprising a third impedance inverter (Z 03); a fourth branch between the second combining node and a third combining node and comprising a fourth impedance inverter (Z 04), wherein the second output is connected to the third combining node via a sixth branch; and a fifth branch between the first output and the third combining node and comprising a fifth impedance inverter (Z 05); wherein the maximum power capacities of the main amplifier, the first peak amplifier, the second peak amplifier, and the third peak amplifier are substantially identical, wherein a supply voltage supplied to the main amplifier, the first peak amplifier, the second peak amplifier, and the third peak amplifier is substantially identical, and wherein the first, second, and third peak amplifiers are configured to turn-on at substantially the same power level of the signal inputted to the Doherty amplifier.