Three-way doherty amplifier

A three-way Doherty amplifier, comprising:

• a three-way power splitter configured to receive an input signal and to output a main signal with a 180° phase shift provided at a main splitter output, a first peak signal with a 90° phase shift provided at a first peak signal output, and a second peak signal without a phase shift provided at a second peak signal output;
• a main path comprising a main amplifier, a first input network coupled between the main splitter output and the main amplifier, and a main impedance load on the main amplifier configured to impose a main phase offset of 180°;
• a first peak path comprising a first peak amplifier, a second input network coupled between the first peak signal output and the first peak amplifier, and a first peak impedance load on the first peak amplifier configured to impose a first peak phase offset of 90°;
• a second peak path comprising a second peak amplifier, a third input network coupled between the second peak signal output and the second peak amplifier, and a second peak impedance load on the second peak amplifier to impose a second peak offset of 360°;
• and
• a combining node configured to provide an output load impedance to output the main signal during an average power saturation and a combination of the main signal, the first peak signal, and the second peak signal during a peak power saturation;
• wherein a first ratio of a gate width of the main amplifier to a first gate width of the first peak amplifier and a second ratio of the gate width of the main amplifier to a second gate width of the second peak amplifier, respectively, are configured to provide a substantially constant load on the main amplifier.

A three-way Doherty amplifier, comprising:

• a two-way power splitter configured to receive an input signal and to output a first signal with a 90° phase shift provided at a first splitter output, and a second signal without a phase shift provided at a second splitter output;
• a first path comprising a main device comprising a first amplifier and a second amplifier, a first input network coupled between the first splitter signal output and the main device, and a first impedance load on the main device configured to impose a phase offset of 90°;
• a second path comprising a third amplifier, a second input network coupled between the second splitter signal output and the third amplifier, and a second peak impedance load on the third amplifier configured to impose a second peak phase offset of 180°;
• and
• a combining node configured to provide an output load impedance to output a main signal during an average power saturation and a combination of the main signal, and the second signal during a peak power saturation;
• wherein a first ratio of a gate width of the first amplifier to a first gate width of the second amplifier and a second ratio of the gate width of the first amplifier to a second gate width of the third amplifier, respectively, are configured to provide a substantially constant load on the main device.

A three-way Doherty amplifier, comprising:

• a main path comprising a main amplifier, a main input network coupled between a main splitter output and the main amplifier, and a main output network coupled between the main amplifier and a combining node;
• a first peak path comprising a first peak amplifier, a second input network coupled between a first peak signal output and the first peak amplifier, and a first peak output network coupled between the first peak amplifier and the combining node;
• and
• a second peak path comprising a second peak amplifier, a third input network coupled between a second peak signal output and the second peak amplifier, and a second peak output network coupled between the second peak amplifier and the combining node,
• wherein a first ratio of a gate width of the main amplifier to a first gate width of the first peak amplifier and a second ratio of the gate width of the main amplifier to a second gate width of the second peak amplifier, respectively, are configured to provide a substantially constant load on the main amplifier.

A three-way Doherty amplifier, comprising:

• a first path comprising a main device comprising a first amplifier and a second amplifier, a first input network coupled between a first splitter signal output and the main device, and a first output network coupled between the main device and a combining node;
• and
• a second path comprising a third amplifier, a second input network coupled between a second splitter signal output and the third amplifier, and a second output network coupled between the third amplifier and the combining node,
• wherein a first ratio of a gate width of the first amplifier to a first gate width of the second amplifier and a second ratio of the gate width of the first amplifier to a second gate width of the third amplifier, respectively, are configured to provide a substantially constant load on the main device.