This article presents a Doherty power amplifier (DPA) based on asymmetric cells with a complex combining load (CCL). In this study, a new and intuitive design technique using the Smith chart is proposed for developing the load network of the CCL-DPA. The peaking amplifier consists of a larger cell size compared to that of the carrier amplifier in order to achieve higher power gain and peak output power in comparison with the conventional CCL-DPAs based on symmetric cells. For verification purposes, the proposed asymmetric CCL-DPA was designed and implemented using 6- and 10-W GaN-HEMTs for the carrier and peaking amplifiers, respectively. For the 1.68-GHz continuous-wave signal, the asymmetric CCL-DPA exhibited a power-added efficiency (PAE) of 68.0% and a drain efficiency (DE) of 73.9% at a peak output power of 43.5 dBm. When an output power back-off of 9.5 dB was used, a PAE of 52.0% and a DE of 54.7% were achieved. Using the long-term evolution signal with a peak-to-average power ratio of 9.6 dB and a signal bandwidth of 10 MHz, a PAE of 53.6%, a DE of 56.4%, and a power gain of 13.5 dB were obtained at a power level of 34.0 dBm. Using a digital predistortion technique, an adjacent channel leakage power ratio of −48 dBc was achieved at the same power level.

中文翻译：

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基于复杂合并负载的非对称单元的Doherty功率放大器

本文介绍了一种基于非对称单元和复杂组合负载（CCL）的Doherty功率放大器（DPA）。在这项研究中，提出了一种使用史密斯圆图的新颖直观的设计技术，用于开发CCL-DPA的负载网络。与基于对称单元的常规CCL-DPA相比，与载波放大器相比，峰化放大器具有更大的单元尺寸，以实现更高的功率增益和峰值输出功率。出于验证目的，分别针对载波放大器和峰值放大器使用6和10 W GaN-HEMT设计和实现了拟议的非对称CCL-DPA。对于1.68 GHz连续波信号，在43.5 dBm的峰值输出功率下，非对称CCL-DPA表现出68.0％的功率附加效率（PAE）和73.9％的漏极效率（DE）。当使用9.5 dB的输出功率补偿时，PAE达到52.0％，DE达到54.7％。使用峰均功率比为9.6 dB且信号带宽为10 MHz的长期演进信号，在200 MHz时获得了53.6％的PAE，56.4％的DE和13.5 dB的功率增益。功率电平为34.0 dBm。使用数字预失真技术，在相同功率水平下，邻信道泄漏功率比达到-48 dBc。