Dual-mode power amplifier with switchable working power and mode switch method

A dual-mode power amplifier with switchable working power, comprising an input transformer, comprising a plurality of output taps, and an input coil is loaded with a to-be-amplified signal;

• an output transformer, comprising a plurality of input taps, the number of the input taps is matched with that of the output taps of the input transformer, and an output coil amplified signals;
• an intermediate switch and a power-amplifier transistor, the plurality of output taps of the input transformer are connected with the input taps of the output transformer via the intermediate switch and the power-amplifier transistor, the intermediate switch is configured with a control signal to conduct the power-amplifier transistor connected in series with the intermediate switch, so that one or more of the output taps of the input transformer are communicated with the input taps of the output transformer, and an amplified signal is output after being transformed by the output transformer;
• and
• a first matching capacitor and a second matching capacitor, the first matching capacitor and the second matching capacitor are connected in parallel between taps at both ends of the input coil of the output transformer and ground.