Nonlinear distortion in helical-scan tape recorders

Parallel channel recording with single channel data rate of at least 150 Mbps is required in digital HDTV and high performance data recorders. Linear densities of these recorders usually lie between 60 and 100 kbpi. Previous studies indicate that nonlinear distortion is dominated by transition shifts arising from one and two bit interactions in thin film disk recording using a thin film head. Our investigation is focused on metal particle tape recording which is characterized by a finite recording depth and a non-uniform transition depth profile. We found that the distortion at high linear densities is mostly transition sharpening as well as transition shift from one bit interaction.