Characteristics of Parametric Reproducing Head for Perpendicular Magnetic Recording

A magnetic reproducing head using parametric oscillation has been developed for use in perpendicular magnetic recording. The head is based on parametric oscillation in a resonant circuit consisting of a single pole-type perpendicular magnetic recording head and four varactor diodes for time-variable capacitance. In this paper, the principle of data reproduction as well as experimental results are described. The characteristics of the output voltage are independent of the signal frequency in the range from DC to 3 MHz. The output voltage is proportional to input signals up to 1 V.