| 摘要 |
Polar modulation input signals to a polar modulated power amplifier include a phase modulated (PM) input signal, which feeds a power amplifier input, and an amplitude modulated (AM) input signal, which provides an envelope supply voltage for the power amplifier. The present invention is a large signal polar modulated power amplifier that extends the effective amplitude range of AM input signals that can be handled by the power amplifier by amplitude modulating the PM input signal using the AM input signal. Amplitude modulating the PM input signal effectively lowers the amplitude of the PM input signal when the amplitude of the AM input signal is lowered, which maintains adequate headroom between the power amplifier's signal input and envelope supply voltage input in the presence of large amplitude AM input signals. As a result, the power amplifier can amplify larger amplitude AM input signals than traditional power amplifier designs.
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