| 摘要 |
<p>A voltage drop across the feed inductance (216, figure 2) of an RF amplifier stage may cause the baseband drain voltage of the transistor (204, figure 2) to differ from the desired envelope-tracking supply voltage. A pre-distortion block 400 estimates the inductive voltage drop from a knowledge of the feed inductance and amplifier impedances and adds the estimated voltage drop to the desired target drain voltage from the shaper 104 so that the drain voltage more closely matches the desired envelope-tracking voltage. A forward model of the supply circuit may be used (figure 5).</p> |
