This work presents the equivalent electrical circuit (EEC) analysis of the 2-way Doherty Power Amplifier (DPA). For this purpose, the sub-amplifiers used in the 2-way DPA are modeled using real voltage sources instead of ideal sources. For the first time, the general voltage and current equations for each node of the EEC are determined using circuit theory with transmission line concepts. The analysis results explain some of the empirical practices carried out in other works to tune the 2-way DPA response, such as offset lines or asymmetrical bias voltages, etc. This analysis allows us to examine the impact that the auxiliary sub-amplifier bias voltage has on the efficiency of the 2-way DPA, suggesting the use of the phase-to-amplitude distortion (AM-PM) of the auxiliary sub-amplifier to eliminate the compensation lines that are commonly implemented arbitrarily in the 2-way DPA, whose objective is to synchronize the output signals of the subamplifiers. The experimental data of a 20 W (43 dBm) 2-way DPA designed and fabricated for a central frequency of 1.875 GHz with GaN transistors validate the proposed idea, resulting in a compact design and a significantly reduced design time.

中文翻译：

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设计无失调补偿线的 Doherty 功率放大器


这项工作介绍了 2 路 Doherty 功率放大器 (DPA) 的等效电路 (EEC) 分析。为此，2 路 DPA 中使用的子放大器使用真实电压源而不是理想电压源进行建模。首次使用电路理论和传输线概念确定 EEC 每个节点的通用电压和电流方程。分析结果解释了其他工作中为调整 2 路 DPA 响应而进行的一些经验做法，例如偏移线或不对称偏置电压等。该分析使我们能够检查辅助子放大器偏置电压的影响对2路DPA的效率有影响，建议使用辅助子放大器的相位幅度失真（AM-PM）来消除2路DPA中通常任意实施的补偿线，其目的是同步子放大器的输出信号。采用 GaN 晶体管设计和制造的中心频率为 1.875 GHz 的 20 W (43 dBm) 2 路 DPA 的实验数据验证了所提出的想法，从而实现了紧凑的设计并显着缩短了设计时间。