| 摘要 |
A multi-frequency band amplifier is operable to receive a multi-frequency band input signal and to provide an amplified multi-frequency output signal at an amplifier output. It comprises a Doherty amplifier with plural carrier amplifiers each amplifying a sub-band and a single peaking amplifier amplifying all sub-bands. In a further aspect, there is provided a power supply control for a power amplifier, involving determining an input signal modulation profile to set a threshold and a corresponding supply voltage, and, upon detecting signal peaks exceeding the threshold, smoothly varying the supply voltage for the amplifier. Accordingly, efficiency gains in amplifier operation may be achieved without the need to apply true envelope tracking techniques. |
