| 赵亚锋,王永添,王煜森,梅思涛,赵贻玖,王厚军.Volterra级数模型下的ADC非线性校正技术研究[J].电子测量与仪器学报,2025,39(6):11-18 |
| Volterra级数模型下的ADC非线性校正技术研究 |
| Volterra series-based techniques for ADC nonlinearity calibration |
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| DOI： |
| 中文关键词: 模数转换器 非线性误差 Volterra级数 数字后校正 |
| 英文关键词:ADC nonlinearity volterra series digital post-calibration |
| 基金项目:四川省自然科学基金面上项目（2024NSFSC0469）资助 |
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| Author | Institution |
| Zhao Yafeng | Shenzhen Institute for Advanced Study,University of Electronic Science and Technology of China, Chengdu 611731,China |
| Wang Yongtian | Siglent Technologies Co., Ltd., Shenzhen 518101,China |
| Wang Yusen | Shenzhen Institute for Advanced Study,University of Electronic Science and Technology of China, Chengdu 611731,China |
| Mei Sitao | School of Automation Engineering, University of Electronic Science and Technology of China, Chengdu 611731，China |
| Zhao Yijiu | School of Automation Engineering, University of Electronic Science and Technology of China, Chengdu 611731，China |
| Wang Houjun | School of Automation Engineering, University of Electronic Science and Technology of China, Chengdu 611731，China |
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| 摘要点击次数: 13 |
| 全文下载次数: 9 |
| 中文摘要: |
| 模数转换器（ADC）的性能决定了采集系统的性能优劣，随着采样率和带宽的提升，非线性误差相较于线性误差具有更大的危害。针对频率相关的ADC非线性误差，提出一种基于正弦拟合结合归一化最小均方算法（NLMS）进行自适应参数估计的方法，对ADC采样数据进行数字后校正。该方法首先对ADC采集的单音信号进行正弦拟合，再基于拟合输出和Volterra级数模型重新构建非线性误差信号。采用NLMS算法对Volterra级数模型相关参数进行自适应估计，当各参数趋于收敛时，经校正后的ADC采样序列与拟合输出之间的偏差接近为0。该方法只需要较少的采样点即可收敛，且不涉及复杂运算，资源开销较少。仿真和实验验证了算法的有效性。在仿真验证中，单音正弦波信号经所提出的方法校正后，2次谐波和3次谐波分别下降了超过20和15 dB；宽带多音信号经校正后，非线性杂散整体“下降”超过15 dB。在一个20 GSPS采样率的硬件平台进行验证也得到了较好的校正效果，系统无杂散动态范围“提升”高于10 dB。 |
| 英文摘要: |
| The performance of an analog-to-digital converter (ADC) determines the quality of the entire acquisition system. With the increase in sampling rate and bandwidth, nonlinear errors pose a greater threat than linear errors. This paper proposes an adaptive parameter estimation method based on sine wave fitting combined with the normalized least mean squares (NLMS) algorithm to calibrate frequency-dependent nonlinear errors in ADCs through digital post-calibration. The method first performs sine wave fitting on the single-tone signal collected by the ADC and then reconstructs the nonlinear error signal based on the fitting output and the Volterra series model. The NLMS algorithm is employed to adaptively estimate the parameters related to the Volterra series model. When the parameters converge, the deviation between the corrected ADC sampling sequence and the fitting output approaches zero. This method requires only a small number of sampling points to converge and involves no complex computations, resulting in low resource overhead. Simulations and experiments have validated the effectiveness of the proposed algorithm. In the simulation, the second harmonic and third harmonic components are attenuated by more than 20 and 15 dB, respectively. Furthermore, the overall nonlinear spurious components of the wideband multi-tone signal are reduced by more than 15 dB after calibration. The proposed method was validated on a hardware platform with a sampling rate of 20 GSPS and demonstrated effective calibration performance, resulting in an overall improvement in the spurious-free dynamic range (SFDR) of approximately 10 dB. |
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