The invention relates to a manufacturing method of a power
amplifier for improving power back-off efficiency, which belongs to the technical field of
radio frequency microwave circuits, and comprises the following steps: step 1, based on load characteristics of an active device, determining an optimal efficiency impedance point under linear output power as optimal impedance of
amplifier design; step 2, pulling out the determined optimal impedance by using a load pulling technology or LOADPULL, and drawing the optimal impedance on an SMITH original drawing; 3, based on the optimal impedance obtained through traction, low-loss
impedance matching is achieved through the equal Q matching technology, loss and bandwidth are compatible, and impedance change and
frequency band shaping are completed; 4, a two-stage or multi-stage amplification structure is adopted, and nonlinear compensation is realized by controlling grid voltages of front-stage and back-stage
active devices and utilizing front-stage and back-stage
gain compression and expansion characteristics; the method has the beneficial effects that the linear output power optimal efficiency impedance point is selected as the optimal impedance of the
amplifier design, and the amplifier maintains higher linear output power and has higher
rollback efficiency.