The scapegoat of the low-efficiency is usually the last stage----output stage of the transmitter. Traditionally, power amplifiers are the output stages and classified in two main types----current mode and switching mode.的翻译：正在翻译，请等待... 什么意思？中文翻译英文，英文翻译中文，怎么说？

的替罪羊了效率低的通常是最后阶段的发射器的输出级-----。传统上,功率放大器的输出级和分为两大类------当前模式和切换模式。