An experimental study of the effect of thermal decay on noise and nonlinear distortions in perpendicular media
An experimental study of the effect of thermal decay on noise and nonlinear distortions in perpendicular media
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垂直介质中热衰减对噪声和非线性畸变影响的实验研究
DOI：
10.1109/tmag.2004.829311
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发表时间：
2004
影响因子：
2.1
通讯作者：
Dean Palmer
中科院分区：
文献类型：
--
作者：
Wenzhong Zhu;Hong Zhou;J. Judy;Dean Palmer
使用伪随机序列研究了噪声和非线性失真的时间依赖性。基于Karhunen-Loeve展开，通过曲线拟合过渡噪声与最显著本征模的关系，将过渡噪声和直流剩磁噪声从总的介质噪声中分离出来。结果表明，随着时间的推移，过渡噪声功率和信号下降，直流剩磁噪声功率增加，导致总的信噪比下降。利用提取的双脉冲技术，发现随着时间的延长，主峰变窄，25-B位置的正回波增加，这表明在垂直介质中，低频分量的衰减比高频分量的衰减快。
The time dependences of both noise and nonlinear distortions were studied using pseudorandom sequences. Transition noise and dc remanence noise were separated from the total media noise by curve fitting the transition noise with the most significant eigenmodes based on the Karhunen-Loeve expansion. The results show that the transition noise power and the signal decrease and the dc remanence noise power increases with time, resulting in a degradation of the total signal to noise ratio. Using the extracted dipulse technique, it was found that the main peak narrowed and a positive echo at 25-b position increased with time, which indicates that the decay of low-frequency components is faster than that of high-frequency components in perpendicular media.