| 摘要 |
A system and method for providing a highly efficient linear transmitter compatible with a radio capable of operating in one of several modes. In a normal mode of operation, the radio frequency power amplifier (RFPA 112) runs in envelope tracking mode. Accordingly, the RFPA supply voltage follows the envelope of the linear modulation. In an alternate mode of operation, the supply modulator (102) is locked to a fixed DC voltage. A high efficiency level is maintained in both the normal mode and the alternate mode by using a single agile DC-DC converter to supply the RFPA. The converter input voltage is switched depending on the mode of operation. |
