Continuous mode class-J radio-frequency (RF) power amplifier is a promising technique that extends the operating bandwidth of the conventional class-B power amplifier. However, the maximum theoretical efficiency is limited to that of the class-B power amplifier. In this paper, an enhanced mode of operation for the class-J power amplifier is proposed by incorporating a third harmonic voltage component to produce an optimum waveform for maximizing the fundamental voltage component and thereby to increase the drain efficiency and introduce a new design space. A detailed derivation for the necessary relations of output power, drain efficiency, and the required harmonic load impedances is provided, showing a significant improvement in theoretical maximum efficiency from 78.5 to 89.8%. In order to confirm the developed analytic approach, a 10 W prototype amplifier model was designed and fabricated to operate within the global system for mobile communications (GSM) frequency band 850–950 MHz using a commercial GaN power high electron mobility transistor (HEMT). The experimental results have indicated that the drain efficiency of the circuit varies from 68 to 80% within the desired band.

中文翻译：

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基于二次和三次谐波处理的高效连续模式射频功率放大器

连续模式 J 类射频 (RF) 功率放大器是一种很有前途的技术，可扩展传统 B 类功率放大器的工作带宽。但是，最大理论效率仅限于 B 类功率放大器。在本文中，提出了一种增强的 J 类功率放大器工作模式，通过合并三次谐波电压分量来产生最佳波形，以最大化基波电压分量，从而提高漏极效率并引入新的设计空间。提供了输出功率、漏极效率和所需谐波负载阻抗的必要关系的详细推导，表明理论最大效率从 78.5% 显着提高到 89.8%。为了确认开发的分析方法，使用商用 GaN 功率高电子迁移率晶体管 (HEMT) 设计和制造了一个 10 W 原型放大器模型，以在 850-950 MHz 的全球移动通信系统 (GSM) 频带内运行。实验结果表明，电路的漏极效率在所需频带内从 68% 变化到 80%。