| 摘要 |
<p>A multi-mode power amplifier (200, 300) includes a drive stage (210, 310) with a variable gain mode which is always in an operation mode, a plurality of output stages (225, 240, 320, 325) which are connected in parallel to provide a multi-mode output, and a switch-controlled load match network (280, 340) which is connected with the output stages (225, 240, 320, 325) and provides an optimal output load impedance to the output stages (225, 240, 320, 325) according to a power range. The efficiency in the low-power mode is improved whereas the efficiency in the high-power mode of the power amplifier is not affected, thus the lifetime of a cell is prolonged, and it is stable in the performance, high in the average efficiency and simple in the circuit.</p> |
