Method, apparatus and system for envelope tracking

A system for envelope tracking comprising:

• a transistor;
• a radio frequency (RF) transistor;
• a driver;
• a switcher current source;
• and
• a subtracting network;
• wherein the system is configured such that when an envelope voltage is less than a predetermined voltage value, the RF transistor is configured for decreasing an amount of absorbed biasing current, and when the envelope voltage is greater than a predetermined voltage value, the RF transistor is configured for increasing an amount of absorbed biasing current.

A method comprising:

• providing an envelope modulator apparatus, the apparatus including a transistor, radio frequency (RF) transistor, a driver, a switcher current source, and a subtracting network;
• modulating, at the subtracting network, a gate of the RF transistor based on an envelope error voltage;
• and
• sinking, at the RF transistor, redundant biasing current generated by the RF transistor.