| 摘要 |
A radio transceiver (100) has both a radio frequency power amplifier (102) and a relatively high output audio power amplifier (110). The RFPA amplifies a linearly modulated signal. A shared power regulator (108) provides supply voltage to both amplifiers at the same time. However, usually only one is active at any given time, and hence the supply voltage is controlled so as to follow the envelope of the signal being amplified, whether it is the transmit signal or the audio signal. When both amplifiers are active, the supply voltage can be set to a fixed level, or it can follow the higher of the two envelopes.
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