Doherty power amplifiers (DPAs) [1] are widely used as basestation PAs in modern wireless communication systems and have been well-reviewed [2]. Due to its mechanism of load modulation, the DPA exhibits an additional efficiency peak at a certain output power back-off (OBO). This makes the DPA highly desirable for amplifying modulated signals with high peak-to-average power ratios (PAPRs). However, there still are limitations that restrict its use in modern and future wireless communication systems. To meet the insatiable demand for higher data rates, modulated signal formats require an everhigher PAPR (>6 dB). This, in turn, means that the DPA needs to operate at a greater OBO >6 dB). Hence, the design of extended back-off DPAs is of great interest to engineers. Broadband operation is also required, but, unfortunately, the DPA?s efficiency at back-off decreases with an increase in bandwidth. Therefore, a technique to achieve high efficiency at back-off, not at the expense of the bandwidth, is urgently needed.

中文翻译：

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治理 Doherty 功率放大器中的谐波 [应用笔记]


Doherty 功率放大器 (DPA) [1] 广泛用作现代无线通信系统中的基站 PA，并且已得到广泛好评 [2]。由于其负载调制机制，DPA 在一定的输出功率回退 (OBO) 下表现出额外的效率峰值。这使得 DPA 非常适合放大具有高峰均功率比 (PAPR) 的调制信号。然而，仍然存在限制其在现代和未来无线通信系统中使用的局限性。为了满足对更高数据速率的永不满足的需求，调制信号格式需要更高的 PAPR (>6 dB)。这反过来意味着 DPA 需要在更大的 OBO >6 dB 下运行。因此，扩展回退 DPA 的设计引起了工程师的极大兴趣。宽带操作也是必需的，但不幸的是，DPA 的回退效率会随着带宽的增加而降低。因此，迫切需要一种在退避时实现高效率而不以牺牲带宽为代价的技术。