微小平面电感线圈近场涡流效应模型

Near-field eddy currents in small planar inductance coils

微小平面电感线圈是一种新型的近场电涡流检测敏感器件,能够应用于复杂表面之间和微机电系统中实现准确的位移测量或无损检测。为了研究微小平面电感线圈的近场涡流效应对其自感和阻抗的影响规律,以轴对称时谐电磁场理论为基础,根据微小平面线圈近场涡流效应的特点,建立了描述微小平面线圈的自感和阻抗变化的数学模型,并进行了详细的模型解析和实验验证。验证结果表明,建立的数学模型具有很强的可计算性,并能够与实验结果很好地相符合,可以为微型平面线圈电涡流传感器的设计提供依据和指导。

A small planar inductance coil is a sensitive non-contact device whose measurements are based on the near-field eddy current. The coil can be used for nondestructive measurements of displacements or distances between very small surfaces, such as in micro-electro-mechanical systems. The relationship between the near-field eddy current and the free inductance and impedance of the coil was modeled based on axially symmetric time-harmonic electromagnetic theory. The coil was also tested experimentally. The model results agree well with the experimental data verifying that the model can be used for the design of small planar coil eddy current sensors.