Analysis of impedance characteristics of meander coil

We have developed a meander coil type linear sensor. When a detection coil is moved on a scale coil, mutual inductance fluctuates according to the displacement, causing the impedance change of detection coil. Therefore, displacement can be detected by using this impedance change. Impedance becomes like a sine wave form and impedance variation increases by resonating the coil, compared with the case when the coil is not resonating. When the width of the detection coil and scale coil are 0.5 and 0.6 mm respectively, impedance variation has its maximum of 38.6 Ω