This article presents the design techniques for a multimode multiband (MMMB) linear RF power amplifier (PA) with a high efficiency, suitable for wireless handset multichip modules. The PA operates with high efficiency at the saturated output power and maintains high linearity with an enhanced efficiency at the back-off power. It is, thus, able to operate in multimodes (saturated/linear) and covers multibands (814–915 MHz; bands: 5/8/18/19/20/26) without reconfiguration, representing a novel solution for the converged PA module architecture to reduce the number of PAs within the handset. A new technique to the handset industry, class-J, is adopted to improve the efficiency while maintaining the linearity. To the best of our knowledge, this work provides the first implementation of the class-J using the GaAs heterojunction bipolar transistor (HBT) technology in the multichip PA modules. The utilization of the GaAs HBT adds more degrees of freedom to enhance the linearity. A PA module, consisting of a GaAs HBT die mounted on a four-layer laminate, is designed. The die is fabricated using the flip-chip technology. The output matching network and the control/bias network are fabricated on the laminate using the printed inductors and the surface-mount device (SMD) capacitors. The results validate the design techniques, showing 2G power added efficiency (PAE) 62%, 2.5G error vector magnitude (EVM) ≤ 3%, and 3G adjacent channel leakage ratio (ACLR) of 5MHz ≤ −35 dBc. The design achieves a higher PAE than other reported reconfigurable and complex MMMB PAs, with comparable linearity.

中文翻译：

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一种利用 GaAs HBT 用于手机模块的高效线性多模多频带 J 类功率放大器

本文介绍了适用于无线手机多芯片模块的高效率多模多频带 (MMMB) 线性射频功率放大器 (PA) 的设计技术。PA 在饱和输出功率下以高效率运行，并在回退功率下保持高线性度并提高效率。因此，它无需重新配置即可在多模（饱和/线性）下运行并覆盖多频段（814–915 MHz；频段：5/8/18/19/20/26），代表了融合 PA 模块的新解决方案架构以减少手机内的 PA 数量。采用了手机行业的一项新技术，J 类，以在保持线性度的同时提高效率。据我们所知，这项工作首次在多芯片 PA 模块中使用 GaAs 异质结双极晶体管 (HBT) 技术实现了 J 类器件。GaAs HBT 的使用增加了更多的自由度以增强线性度。设计了一个 PA 模块，由安装在四层层压板上的 GaAs HBT 芯片组成。芯片采用倒装芯片技术制造。输出匹配网络和控制/偏置网络使用印刷电感器和表面贴装器件 (SMD) 电容器在层压板上制造。结果验证了设计技术，显示 2G 功率附加效率 (PAE) 62%，2.5G 误差矢量幅度 (EVM) ≤ 3%，3G 邻道泄漏比 (ACLR) 5MHz ≤ −35 dBc。该设计实现了比其他报道的可重构和复杂 MMMB PA 更高的 PAE，具有可比的线性度。