Experimental studies of shingled recording using contact recording test system

In this paper, a high resolution perpendicular contact recording test system has been made and used for studying signal and noise properties of a new proposed recording scheme, Shingled Magnetic Recording (SMR). The tester uses modern tunnel magneto-resistive (TMR) head as a sensor and single write pole to write sequence of data on the sample. The write and read processes operate at very low scan rate in physical contact with the sample. Thus, the maximum performance, signal and noise characteristics can be obtained without the effects of spacing loss, thermal asperities and flying height uncertainties. The tester includes standard magnetic media test parameters such as saturation, roll-off curves, transition noise and two-dimensional (2D) readback image. It was found that the roll-off curves follow the same trend found in conventional recording except at low linear density, where shingled recording gave slightly higher voltage amplitudes compared to conventional recording attributed to constructive, inter-track interference. Transition noise was measured using time domain techniques. The measurements indicated a strong noise signal on shingled recording and its peak was around the D50 point of the medium.