The dependence of overwrite on non-linear transition shift

Overwrite (OW) is a function of both the density of the low frequency pattern and the density of the high frequency pattern. The dependence of overwrite on high frequency pattern density is due to interactions of hard transition shift with non-linear transition shift (NLTS) to produce timing modulation which is greater than the sum of these separate effects. Experimental results show that this interaction can degrade overwrite performance by as much as 6 dB.