A new modulator for digital RF power amplifiers utilizing a wavetable approach
A new modulator for digital RF power amplifiers utilizing a wavetable approach
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采用波表方法的数字射频功率放大器的新型调制器
DOI：
10.1017/s1759078717000770
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发表时间：
2017
影响因子：
1.4
通讯作者：
W. Heinrich
中科院分区：
文献类型：
--
作者：
F. Hühn;A. Wentzel;W. Heinrich
本文首次提出了一种基于波表的数字射频功率放大器高速二进制输入信号的编码方案。该方法使脉冲形成电路的时域处理能力的利用最大化。主要特点是与普通数字调制器相比，输出频谱纯度大大提高，能够根据任何给定的脉冲形成硬件调整调制器，以及内置的信号校正选项，无需额外的计算成本。为了给调制器的行为和它的可能性，以适应不同的硬件约束的第一印象，模拟进行不同的参数变化和不同的基带带宽。此外，所提出的概念与任意波形发生器进行仿真，以收集额外的测量数据。对于900 MHz的5 MHz宽带码分多址（WCDMA）信号（6.5 dB峰均功率比），记录到0.26%的误差矢量幅度（EVM）和优于58 dB的相邻信道泄漏比（ACLR）。据作者所知，这些是迄今为止在没有数字预失真的情况下仍保持最大功率编码效率的单比特编码方案所达到的最佳值。
This paper presents for the first time a wavetable-based coding scheme to generate a high-speed binary input signal for digital RF power amplifiers. The approach maximizes the utilization of the time domain handling capabilities of the pulse forming circuit. Key features are a greatly improved output spectrum purity in comparison with common digital modulators, the ability to adjust the modulator to any given pulse forming hardware and a built-in signal correction option that comes without additional computational cost. To give a first impression on the modulators behavior and its possibilities to adapt to different hardware constraints, simulations are carried out for different parameter variations and for different baseband bandwidths. Furthermore, the proposed concept is emulated with an arbitrary waveform generator to gather additional measurement data. For a 5 MHz wideband code division multiple access (WCDMA) signal (6.5 dB peak-to-average power ratio) at 900 MHz, an error vector magnitude (EVM) of 0.26% and better than >58 dB adjacent channel leakage ratio (ACLR) were recorded. To the authors’ knowledge, these are the best values achieved so far for a single-bit coding scheme without digital predistortion that still maintains maximum power coding efficiency.