Areal-Density Capability Measurement Based on 747 Test in Magnetic Recording Systems
A method is presented for determining the areal density (AD) capability of a magnetic recording system based on a set of 747 tests taken over a range of linear densities. By fitting the measured results with a suitable functional form, we can readily predict off-track capability (OTC) at any combination of linear density and track density. Conversely, for a given OTC requirement, we can immediately find the maximum AD that can be reached and the bit aspect ratio required to achieve it. Our results also reveal the effect of skew angle on AD and match well with previous results for perpendicular magnetic recording.
Optimal bit aspect ratio for maximum areal density
An analysis is given to determine the maximum areal density achievable in digital magnetic recording and the associated optimal bit aspect ratio. Typical transducer-media parameters are selected, a conventional two-path peak detection data channel is modeled, and error probability is determined as a function of track density and bit density so that maximal areal density and optimal user bit aspect ratio can be determined. >
Media limitations on achievement of maximum detection window
The recording performance of a digital recording system is primarily dependent upon the isolated half pulse width (T 50 ), signal amplitude, intersymbol interference (ISI), signal to noise ratio (SNR) and the horizontal detection window margin (T m ). These characteristics are related to the thickness and magnetic properties of the media, as well as the head/media interface. This paper addresses the relationship of the media characteristics in longitudinal digital magnetic recording for both particulate and thin film media to the overall recording system performance. The results are shown to proceed from further development of the quasi-optimum time containment filter analysis for media noise dominant and electronic (white) noise dominant recording channels [1], [2].