Frequency response in digital magnetic recording

A previous analysis of the length of the isolated transition in digital magnetic recording, which used an analytical model of the write process, is extended to predict the output of the readback head for an alternating series of transitions with variable spacing, which is referred to as spatial frequency response. A convolution integral is derived which is used to calculate the spatial frequency response of a wide-pole-tip readback head to a series of arctangent transitions. For high densities it is found that the response is nearly sinusoidal and an analysis is given of the write process for sinusoidal magnetization, which is then also used to calculate spatial frequency response. The theoretical results are compared with experiments on chemically deposited magnetite films and agreement with the convolution integration is reasonable.