Accurate approximation of fields and spectral response functions for perpendicular recording heads

Solutions for the magnetic potential in rectangular regions with simple bou ndary conditions are used to approximate the two-dimensional potential in t he head face plane of a recording head. This method of approximation can be applied to any recording head with rectangular corners, in the presence of an underlayer, The slot approximation is demonstrated for ring heads and s hielded (magnetoresistive) pole heads. The quarter plane approximation is g iven for application to finite-length heads. Estimates of the field compone nts and the spectral response function are derived from the approximate pot ential. The simple slot approximation is shown to be at least as accurate a s other, often more complicated, methods of approximation, Most significant ly, both the slot and the quarter-plane approximations are easy to apply an d need no prior knowledge of the head field of the particular geometry unde r consideration.