A read channel for magnetic recording

Recording physics and organization of data on a disk

Bane V Vasic, Miroslav Despotović

Research output: Chapter in Book/Report/Conference proceedingChapter

Abstract

A steady increase in recording densities and data rates of magnetic hard drives during last 15 years are mostly due to advances in recording materials, read/write heads, and mechanical designs. The role of signal processing and coding has been to make the best use of the capacity and speed potentials offered by these advances. As the recording technology matures, the read channel is becoming more and more advanced, reaching the point where it uses equally or even more complicated signal processing, coding 18-1 To record data on a surface of a disk, the modulated signal current, typically bipolar, is passed through the electromagnet coils thus generating a fringing magnetic field. The fringing magnetic field creates a rémanent magnetization on the ferromagnetic surface, i.e., the ferromagnetic surface becomes permanently magnetic. The magnetic domains in the surface act like tiny magnets themselves and create their own fringing magnetic field above the ferromagnetic surface. The data are recorded in concentric tracks as a sequence of small magnetic domains with two senses of magnetization depending on a sign of writing current. In this, so-called saturation recording, the amplitude of two writing current signal levels are chosen sufficiently large so as to magnetize to saturation the magnetic medium in one of two directions. In this way, the nonlinear hysteresis effect does not affect domains recorded over previously recorded ones.

Original languageEnglish (US)
Title of host publicationDigital Systems and Applications
PublisherCRC Press
ISBN (Electronic)9780849386206
ISBN (Print)9780849386190
DOIs
StatePublished - Jan 1 2017

Fingerprint

Magnetic recording
Physics
Magnetic domains
Magnetic fields
Magnetization
Signal processing
Electromagnets
Magnets
Hysteresis

ASJC Scopus subject areas

  • Computer Science(all)
  • Engineering(all)

Cite this

A read channel for magnetic recording : Recording physics and organization of data on a disk. / Vasic, Bane V; Despotović, Miroslav.

Digital Systems and Applications. CRC Press, 2017.

Research output: Chapter in Book/Report/Conference proceedingChapter

Vasic, Bane V ; Despotović, Miroslav. / A read channel for magnetic recording : Recording physics and organization of data on a disk. Digital Systems and Applications. CRC Press, 2017.
@inbook{f20b2b0b9a6643ba934373d0d0fd35c4,
title = "A read channel for magnetic recording: Recording physics and organization of data on a disk",
abstract = "A steady increase in recording densities and data rates of magnetic hard drives during last 15 years are mostly due to advances in recording materials, read/write heads, and mechanical designs. The role of signal processing and coding has been to make the best use of the capacity and speed potentials offered by these advances. As the recording technology matures, the read channel is becoming more and more advanced, reaching the point where it uses equally or even more complicated signal processing, coding 18-1 To record data on a surface of a disk, the modulated signal current, typically bipolar, is passed through the electromagnet coils thus generating a fringing magnetic field. The fringing magnetic field creates a r{\'e}manent magnetization on the ferromagnetic surface, i.e., the ferromagnetic surface becomes permanently magnetic. The magnetic domains in the surface act like tiny magnets themselves and create their own fringing magnetic field above the ferromagnetic surface. The data are recorded in concentric tracks as a sequence of small magnetic domains with two senses of magnetization depending on a sign of writing current. In this, so-called saturation recording, the amplitude of two writing current signal levels are chosen sufficiently large so as to magnetize to saturation the magnetic medium in one of two directions. In this way, the nonlinear hysteresis effect does not affect domains recorded over previously recorded ones.",
author = "Vasic, {Bane V} and Miroslav Despotović",
year = "2017",
month = "1",
day = "1",
doi = "10.1201/9780849386206",
language = "English (US)",
isbn = "9780849386190",
booktitle = "Digital Systems and Applications",
publisher = "CRC Press",

}

TY - CHAP

T1 - A read channel for magnetic recording

T2 - Recording physics and organization of data on a disk

AU - Vasic, Bane V

AU - Despotović, Miroslav

PY - 2017/1/1

Y1 - 2017/1/1

N2 - A steady increase in recording densities and data rates of magnetic hard drives during last 15 years are mostly due to advances in recording materials, read/write heads, and mechanical designs. The role of signal processing and coding has been to make the best use of the capacity and speed potentials offered by these advances. As the recording technology matures, the read channel is becoming more and more advanced, reaching the point where it uses equally or even more complicated signal processing, coding 18-1 To record data on a surface of a disk, the modulated signal current, typically bipolar, is passed through the electromagnet coils thus generating a fringing magnetic field. The fringing magnetic field creates a rémanent magnetization on the ferromagnetic surface, i.e., the ferromagnetic surface becomes permanently magnetic. The magnetic domains in the surface act like tiny magnets themselves and create their own fringing magnetic field above the ferromagnetic surface. The data are recorded in concentric tracks as a sequence of small magnetic domains with two senses of magnetization depending on a sign of writing current. In this, so-called saturation recording, the amplitude of two writing current signal levels are chosen sufficiently large so as to magnetize to saturation the magnetic medium in one of two directions. In this way, the nonlinear hysteresis effect does not affect domains recorded over previously recorded ones.

AB - A steady increase in recording densities and data rates of magnetic hard drives during last 15 years are mostly due to advances in recording materials, read/write heads, and mechanical designs. The role of signal processing and coding has been to make the best use of the capacity and speed potentials offered by these advances. As the recording technology matures, the read channel is becoming more and more advanced, reaching the point where it uses equally or even more complicated signal processing, coding 18-1 To record data on a surface of a disk, the modulated signal current, typically bipolar, is passed through the electromagnet coils thus generating a fringing magnetic field. The fringing magnetic field creates a rémanent magnetization on the ferromagnetic surface, i.e., the ferromagnetic surface becomes permanently magnetic. The magnetic domains in the surface act like tiny magnets themselves and create their own fringing magnetic field above the ferromagnetic surface. The data are recorded in concentric tracks as a sequence of small magnetic domains with two senses of magnetization depending on a sign of writing current. In this, so-called saturation recording, the amplitude of two writing current signal levels are chosen sufficiently large so as to magnetize to saturation the magnetic medium in one of two directions. In this way, the nonlinear hysteresis effect does not affect domains recorded over previously recorded ones.

UR - http://www.scopus.com/inward/record.url?scp=85060425483&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85060425483&partnerID=8YFLogxK

U2 - 10.1201/9780849386206

DO - 10.1201/9780849386206

M3 - Chapter

SN - 9780849386190

BT - Digital Systems and Applications

PB - CRC Press

ER -