基于国产ADC芯片的TIADC系统时间误差自适应校准算法

TIADC system time error adaptive calibration algorithm based on domestic ADC chip

武器及其测试系统的高精度与国产化是我们国家现在不得不面对的严峻问题,当数据采集系统的采样率达到GSPS量级时,目前的国产ADC芯片很难达到,因此在不降低采样精度的前提下,提出多片ADC进行阵列化采样的方法提高系统的采样率。针对TIADC系统存在的通道失配问题,提出了基于一阶统计量的自适应误差估计算法与改进Farrow时延滤波器的校正方法,并对4通道TIADC系统的时间误差估计提出新的估计策略。仿真与实验结果表明,该算法能够对时间失配误差进行精确估计,同时能够有效地抑制杂散分量,相比校正前的数据,无杂散动态范围提高20 dB,对解决高速高精度数据采集装备国产化问题具有重要的现实意义。

The high precision and localization of weapons and their test systems are the serious problems that our country has to face.When the sampling rate of the data acquisition system reaches the GSPS level,current domestic ADC chips are hardly applicable.Therefore,under the prerequisite of not reducing sampling accuracy,a method of array sampling with multiple ADCs is proposed to improve the sampling rate of the system.Aiming at the channel mismatch problem existing in TIADC systems,an adaptive error estimation algorithm based on first-order statistics and correction method of improved Farrow time delay filter is proposed,and a new estimation strategy for the time error estimation of the 4-channel TIADC system is proposed.Simulation and experiment results show that the algorithm can accurately estimate the time mismatch error and effectively suppress spurious components.Compared with the data before correction,the spurious-free dynamic range is increased by 20 dB.The proposed method has important practical significance for solving the localization issue of high-speed and high-precision data acquisition equipment.