A Quasi-Balanced Power Amplifier With Feedforward Linearization
A Quasi-Balanced Power Amplifier With Feedforward Linearization
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具有前馈线性化的准平衡功率放大器
DOI：
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发表时间：
2022
影响因子：
3
通讯作者：
Byung
中科院分区：
文献类型：
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作者：
M. Jung;S. Min;Byung
本文提出了一种由准平衡功率放大器（QBPA）和相消级组成的前馈线性化功率放大器（FFW PA），它通过抑制三阶互调（IM 3）来实现。QBPA级用于提取IM 3音调，FFW技术用于在消除级中抑制IM 3音调。与传统的FFW放大器相比，所提出的FFW PA在QBPA级中不需要移相器和衰减器，并且在消除级中不需要采用高增益辅助放大器。在3.5 GHz时，所设计的FFW功率放大器的输出参考1 dB增益压缩点为+30.8 dBm，比FFW功率放大器中使用的单功率放大器高3.8 dB。在7.8 dB回退输出功率（+20 dBm/tone）的双音测量中，FFW PA的IMD 3电平为−54.6 dBc，比传统平衡PA低14 dB。在20 MHz带宽和+23 dBm发射功率的64正交幅度调制信号的LTE评估中，所提出的FFW PA的测量输出频谱显示出−48.7 dB的相邻信道泄漏比，比传统的平衡PA提高了6.6 dB。
In this letter, a feedforward (FFW) linearized power amplifier (FFW PA) composed of quasi-balanced PA (QBPA) and cancellation stages is proposed by suppressing the third-order intermodulation (IM3) tones. The QBPA stage is used for extracting the IM3 tones and the FFW technique is used for suppressing IM3 tones in the cancellation stage. Compared to the conventional FFW amplifier, the proposed FFW PA does not require a phase shifter and attenuator in the QBPA stage and does not need to employ a high-gain auxiliary amplifier in the cancellation stage. The measured output-referred 1-dB gain compression point of the proposed FFW PA is +30.8 dBm at 3.5 GHz, which is 3.8 dB higher than the single PA used in the FFW PA. In two-tone measurement at 7.8-dB back-off output power (+20 dBm/tone), the IMD3 level of the FFW PA is −54.6 dBc, which is lower by 14 dB compared to that of the conventional balanced PA. In the LTE evaluation with a 64 quadrature amplitude modulation signal in 20-MHz bandwidth and +23-dBm transmitting power, the measured output spectra of the proposed FFW PA exhibit an adjacent channel leakage ratio of −48.7 dB, which is a 6.6-dB improvement over the conventional balanced PA.