Sensitivity function and spectral response without gap-nulls of an inductive perpendicular head geometry

An inductive head geometry without gap nulls for perpendicular magnetic recording has been modeled theoretically and experimentally. In particular, the field produced by two infinitely long and current-carrying strips placed between two highly permeable regions has been calculated. For this special geometry, this stripline model produces a sawtooth field profile for which the Fourier transform shows a very gradual decay with decreasing wavelength without nulls. The spectral sensitivity function for the strip structure is compared to that of a single-pole head. It is anticipated that this high-efficiency read transducer can be used for perpendicular magnetic recording at shorter wavelengths than single-pole-type heads that do show gap nulls