Effect of Bandpass Filters for TA Suppression in Perpendicular Recording System

Abstract

Thermal asperities (TAs) cause a crucial problem in magnetic recording systems because they can distort the readback signal to the extent of causing possible sector read failure. This problem becomes even more severe in perpendicular recording channels because these channels contain a d.c. component. This paper presents a novel TA suppression method by use of a bandpass ¯lter to mitigate the TA effect. We also investigate the effect of different bandpass filters for TA suppression. Results indicate that the proposed TA suppression method using a bandpass filter polynomial G(D) = (1+D)2(1-D) yields lower bit-error rate than the existing ones at the expense of increased complexity, and is also robust to large peak TA amplitudes.