Linear, Passive, Matched Filter for Digital Magnetic Recording

A linear, passive matched filter is developed for the readback portion of digital magnetic recording systems. The filter, by maximizing the signal-to-noise ratio (SNR), improves the reliability of digital magnetic recording. This is necessary because the continuous improvement in magnetic recording resolution has brought about a consequent deterioration in the SNR. For the worst case, namely, when the signal and noise occupy precisely the same band of frequencies, laboratory experiments show an improvement factor of 3.42 in the SNR. The filter tested was of very low cost since it was built with standard off-the-shelf components. It can be easily implemented in any given situation by simple network scaling.