Multiband envelope tracking power amplifier

An apparatus, comprising:

• a first power supply;
• a second power supply;
• a third power supply;
• the first power supply, the second power supply and the third power supply each being narrow-banded;
• a digital predistorter coupled to provide separate bands of a modulation signal for corresponding inputs to the first power supply, the second power supply, and the third power supply;
• the first power supply for generating a first power at a first center frequency;
• the second power supply for generating a second power at a second center frequency spaced apart from the first center frequency;
• the third power supply for generating a third power at a third center frequency spaced apart from both the first center frequency and the second center frequency for a wide-band configuration;
• and
• the second power output from the second power supply and the third power output from the third power supply each coupled to the first power output from the first power supply to provide a multiband power modulation output.

A method, comprising:

• generating a modulation signal with a digital predistorter;
• providing a first band and a second band of the modulation signal respectively to a first power supply and a second power supply;
• generating first power at a first center frequency with the first power supply for envelope tracking responsive to the first band of the modulation signal;
• generating second power at a second center frequency with the second power supply for envelope tracking responsive to the second band of the modulation signal;
• the first power supply and the second power supply each being narrow-banded;
• the second center frequency spaced apart from the first center frequency for a wide-band configuration;
• and
• coupling the second power to the first power to provide a multiband power modulation output.