NOISE IN THIN-FILM INDUCTIVE HEADS

In this paper the sources of thermal noise in thin-film inductive recording heads are investigated. These noise sources are associated with the various losses in the heads. An equivalent circuit model of the head impedance is made whose parameters are fitted to the measured impedance over a 100 MHz frequency range. The head is read out by a low-noise pre-amplifier whose input impedance and input-referred voltage and current noise are also measured. Of the ensuing channel front-end (head plus pre-amplifier), the total noise is determined as well as the relative contributions of the various head and electronics noise sources and their spectral distributions.