Abstract: A calculation method for the value of planar inductor is presented. The effects that determine the merit of planar spiral inductor are analyzed. Based on an electrical model of the micromachined inductor, eddy current effect induced parasitic resistance and the capacitance due to the lossy substrate are carefully studied. The obtained theoretical result shows the value is related to both the inductor geometric size and the operating frequency. An optimized planar inductor can be realized through the theoretical analysis and calculation.

Key words: micromachining,  inductor,  -value,  silicon substrate