Electronic device and method for envelope tracking

A method for envelope tracking (ET), applied to an electronic device having a processor, a modulator, and a power amplifier, comprising:

• the processor receiving a baseband signal;
• the processor executing a first ET shaping function on the baseband signal;
• wherein the first ET shaping function enables that a first voltage from the modulator is equal to an absolute value squared of the baseband signal multiplied by a first constant plus a second constant;
• the processor calculating the first and second constants based on a look-up table;
• the modulator receiving the baseband signal after the first ET shaping function is executed on the baseband signal;
• the modulator detecting the magnitude of the baseband signal;
• the modulator outputting the first voltage according to the magnitude of the baseband signal;
• and
• the power amplifier outputting an amplified signal based on the first voltage;
• wherein the look-up table records a relation curve between the power of the amplified signal and the first voltage when the second ET shaping function is used for envelope tracking.