In this letter, a linearization solution for Doherty power amplifiers (DPAs) based on independently tunable linearizer (ITL) is proposed. The ITL for DPA (DITL) is obtained by vector synthesis of two parallel ITLs; the back-off and gain characteristic is configurable to match the DPAs. To verify the method, a prototype is designed at 3.5 GHz. A DPA with 8.5 dB back-off and 20-MHz wideband signal stimulated is measured, the results show that the adjacent channel power ratio (ACPR) is improved from −32.3 to −44.9 dBc, and the power consumption and cost with performance improvement is comparable to conventional linearizers. The DITL can achieve good performance without codesign with DPA, which is suitable in 5G communication system.

中文翻译：

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用于 Doherty 功率放大器的可配置独立可调线性器

在这封信中，提出了一种基于独立可调线性化器 (ITL) 的 Doherty 功率放大器 (DPA) 线性化解决方案。DPA 的 ITL（DITL）是通过两个平行的 ITL 的载体合成得到的；可配置回退和增益特性以匹配 DPA。为了验证该方法，我们设计了一个 3.5 GHz 的原型。对具有 8.5 dB 回退和 20-MHz 宽带信号激励的 DPA 进行了测量，结果表明，邻道功率比 (ACPR) 从 -32.3 dBc 提高到 -44.9 dBc，并且功耗和成本随着性能的提高为可与传统线性化器相媲美。DITL 无需与 DPA 协同设计即可获得良好的性能，适用于 5G 通信系统。