Approximate Fourier coefficients for gapped magnetic recording heads

An investigation is presented of the number of exact Fourier terms needed to evaluate the field components of a ring head, a slotted plane, and planar heads of various dimension ratios to specified accuracy. Simple approximate formulas for the coefficients of a ring head and a slotted plane are given, and two approximations to the coefficients of a planar head of given dimensions are provided. The accuracy of the field components and the spectral response function, each evaluated with the approximate coefficients, is used to assess the usefulness of these approximations. Both of the approximations for the coefficients of planar heads lead to excellent estimates of the field components.