Reconfigurable DPD Based on ANNs for Wideband Load Modulated Balanced Amplifiers Under Dynamic Operation From 1.8 to 2.4 GHz
Reconfigurable DPD Based on ANNs for Wideband Load Modulated Balanced Amplifiers Under Dynamic Operation From 1.8 to 2.4 GHz
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DOI：
10.1109/tmtt.2021.3091672
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发表时间：
2021-07
影响因子：
4.3
通讯作者：
Estefanía Guillena;Wantao Li;G. Montoro;R. Quaglia;P. Gilabert
中科院分区：
文献类型：
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作者：
Estefanía Guillena;Wantao Li;G. Montoro;R. Quaglia;P. Gilabert
本文提出了一种方法，以确保线性放大的负载调制平衡放大器（LMBA），同时保持功率效率尽可能高的频带范围从1.8到2.4 GHz，其中发送的信号可以呈现不同的带宽（BW）配置。所提出的可重构线性化方法包括，在第一步骤中，调谐LMBA的一些自由参数（依赖于信号BW和操作频率），以权衡线性度和功率效率。在第二步中，两个多用途的自适应数字预失真（DPD）的线性化被认为是适当地结合波峰因数降低（CFR）技术，以满足所需的线性规格。考虑到计算复杂度和线性化性能之间的折衷，可以选择基于人工神经网络的DPD或基于多项式的DPD。实验结果将验证所提出的方法，以保证线性度水平（ACPR <−45 dBc和EVM <1%），在动态传输下的LMBA中具有高功率效率，其中信号带宽（从20 MHz到200 MHz的瞬时带宽）和工作频率（在1.8-2.4 GHz的范围内）都发生变化。
This article proposes a methodology to ensure linear amplification of a load modulated balanced amplifier (LMBA) while keeping the power efficiency as high as possible over a frequency band ranging from 1.8 to 2.4 GHz and where the transmitted signals can present different bandwidth (BW) configurations. The proposed reconfigurable linearization methodology consists of, in a first step, tuning some free parameters (with dependence on the signal BW and frequency of operation) of the LMBA to trade-off linearity and power efficiency. In a second step, two multipurpose adaptive digital predistortion (DPD) linearizers are considered, properly combined with crest factor reduction (CFR) techniques, to meet the required linearity specifications. Either a DPD based on artificial neural networks or a DPD based on polynomials can be selected taking into account the compromise between computational complexity and linearization performance. Experimental results will validate the proposed methodology to guarantee the linearity levels (ACPR <−45 dBc and EVM <1%) with high power efficiency in an LMBA under dynamic transmission, where both the signal BW (from 20 and up to 200-MHz instantaneous BW) and frequency of operation (in the range of 1.8–2.4 GHz) change.