In this letter, the design of a broadband high-efficiency Doherty power amplifier (DPA) with a bandwidth of 1000 MHz for the 5G frequency band is proposed. The postmatching structure is employed to achieve broadband performance. The proposed DPA shows high efficiency at 6-dB output power back-off (OBO) in the entire 1000-MHz band. The DPA has been designed and implemented using commercial GaN HEMTs to validate the high efficiency and broadband characteristics. The fabricated DPA attains a measured 7.1–11.1-dB saturated gain and a 43.2–44.5-dBm saturated power. The 46%–52% and 58.6%–68.9% drain efficiencies are obtained at 6-dB OBO and saturation throughout the design band, respectively. A 20-MHz LTE modulated signal with a peak-to-average power ratio of 7.2 dB is also applied to the proposed DPA at 3.5 GHz. The average output power is 37.2 dBm. The measured ACPR is improved from −27 to −48.9 dBc with digital predistortion (DPD) performed.

中文翻译：

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3.3-4.3GHz 高效宽带 Doherty 功率放大器

在这封信中，提出了一种用于 5G 频段的带宽为 1000 MHz 的宽带高效 Doherty 功率放大器 (DPA) 的设计。采用后匹配结构来实现宽带性能。建议的 DPA 在整个 1000 MHz 频带中以 6 dB 输出功率回退 (OBO) 显示出高效率。DPA 是使用商用 GaN HEMT 设计和实施的，以验证高效率和宽带特性。制造的 DPA 获得了 7.1-11.1-dB 饱和增益和 43.2-44.5-dBm 饱和功率。46%–52% 和 58.6%–68.9% 的漏极效率分别在 6-dB OBO 和整个设计频带的饱和度下获得。峰均功率比为 7.2 dB 的 20 MHz LTE 调制信号也应用于建议的 3.5 GHz DPA。平均输出功率为 37.2 dBm。