Microwave Recording Head Stabilizing Oscillation via Capacitor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current magnetic recording technologies face limitations in achieving high recording densities due to thermal fluctuations and the need for stable high-frequency magnetic fields, which are difficult to maintain with existing spin torque oscillators, leading to instability in magnetization reversal and signal noise ratio.
Innovation Solution
A microwave-assisted magnetic recording head with a spin torque oscillator that generates a stable high-frequency magnetic field by using a capacitor in parallel with the spin torque oscillator to suppress voltage fluctuations and ensure constant voltage application, combined with a read/write IC for controlling the timing and magnitude of magnetic fields, enhancing the areal recording density and signal-to-noise ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the anisotropy energy of the magnetic recording medium is increased to overcome thermal fluctuations, then thermal stability is improved, but the recording magnetic field generation becomes inadequate due to narrow head width, inhibiting recording
Solution Approach 1:
The patent applies periodic high-frequency magnetic fields (microwave frequency) to the magnetic recording medium to induce magnetization precession. This periodic action reduces the effective anisotropy energy barrier dynamically, enabling magnetization reversal even in media with high static anisotropy energy that would otherwise be too stable to reverse with narrow heads
Solution Approach 2:
The patent changes the effective magnetic anisotropy parameter dynamically by applying high-frequency fields. The microwave-assisted field modifies the energy landscape temporarily, creating conditions where magnetization reversal becomes possible with the available head width and field strength
2Productivity
If spin torque oscillators are used to generate high-frequency magnetic fields, then microwave-assisted recording is enabled, but voltage fluctuations cause instability in oscillation frequency and amplitude
Solution Approach 1:
The patent introduces feedback control mechanisms where the oscillation output is monitored and used to adjust the drive voltage. This feedback loop compensates for voltage fluctuations and maintains stable oscillation frequency and amplitude, ensuring consistent high-frequency field generation for reliable recording
Solution Approach 2:
The patent dynamically adjusts the drive voltage parameter to the spin torque oscillator based on detected oscillation characteristics. By changing the voltage parameter in response to instability, the system maintains optimal oscillation conditions despite supply voltage fluctuations
3Productivity
If narrow width magnetic heads are used to achieve high recording density, then areal density is improved, but adequate recording magnetic field generation is precluded
Solution Approach 1:
The patent uses periodic high-frequency magnetic fields to assist magnetization reversal, enabling narrow heads to achieve adequate recording performance. The oscillating field provides additional energy input that compensates for the reduced static field strength from narrower head widths
Solution Approach 2:
The patent replaces reliance on purely mechanical/magnetic field strength from head width with a field-assisted approach using high-frequency electromagnetic fields. This substitution allows narrow heads to achieve the same effective recording capability through microwave assistance
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides a stable high-frequency magnetic field with improved frequency and amplitude stability, enabling higher recording densities and a higher signal-to-noise ratio, overcoming the limitations of existing technologies by reducing fluctuations and maintaining consistent oscillation.
Implementation Method 1
a spin torque oscillator that generates a stable high-frequency magnetic field
Implementation Method 2
applying a high-frequency assisted magnetic field to a magnetic recording medium to induce the magnetization precession in the magnetic recording medium
Implementation Method 3
using a capacitor in parallel with the spin torque oscillator to suppress voltage fluctuations and ensure constant voltage application
Implementation Method 4
a magnetic head and a magnetic recording apparatus for recording information in which magnetization reversal is enhanced by applying a high-frequency assisted magnetic field
Data Source
AI summary
A magnetic recording head for microwave-assisted magnetic recording is disclosed. In one embodiment, a magnetic recording head is for applying a magnetic field from a main pole of said magnetic recording head for recording data to a disk. Further comprising a spin torque oscillator adjacent to said magnetic recording head and is for generating a high-frequency magnetic field at a stable frequency and amplitude. Further comprising a capacitor connected to an upper electrode of said spin torque oscillator via a first resistor and a lower electrode of said spin torque oscillator via a second resistor.