Single gate bias power amplifier circuit with tailored threshold transistors and manufacturing methods thereof

A method of manufacturing a circuitry for amplification, the method comprising:

• forming a first transistor and a second transistor are fabricated on a single semiconductor wafer or on separate semiconductor wafers:
• tailoring a first threshold voltage for the first transistor and a second threshold voltage for the second transistor;
• and
• configuring a single gate bias supply to provide a common gate voltage to the gates of both transistors.

A Doherty power amplifier, comprising:

• a main amplifier comprising a first high electron mobility transistor (HEMT):
• an auxiliary amplifier comprising a second HEMT;
• and
• a single gate bias supply configured to provide a common gate voltage to both the first HEMT of the main amplifier and the second HEMT of the auxiliary amplifier, wherein the first HEMT and the second HEMT have different threshold voltages,
• wherein the first HEMT and the second HEMT are fabricated on the same wafer or on different wafers.