High-Frequency Phase-Locked Oscillator Circuit Stabilization
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Solution Overview
Problem
High-frequency phase-locked oscillation circuits using magnetoresistive elements suffer from unstable oscillating frequencies and wide peak widths, which hinder downsizing and effective phase synchronization.
Innovation Solution
A high-frequency phase-locked oscillation circuit is designed with a magnetoresistive element, a reference signal source, a phase-locked loop circuit, and a filter that cuts off the reference frequency while allowing the oscillating frequency to pass through, ensuring stable oscillation by adding a bias voltage to the magnetoresistive element and using a filter between the frequency divider and the magnetoresistive element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a magnetoresistive element is used as a high-frequency oscillation source to achieve downsizing, then the device size is reduced and manufacturing is simplified, but the oscillating frequency becomes unstable and the peak width increases
Solution Approach 1:
A filter is introduced as an intermediary component between the magnetoresistive element and the frequency divider. This filter selectively removes the reference frequency component from the oscillation signal, allowing only the desired high-frequency oscillation to pass through to the frequency divider, thereby stabilizing the oscillation without requiring larger components
Solution Approach 2:
The invention changes the frequency domain parameters of the signal by using a filter to eliminate the reference frequency component. This parameter transformation converts the unstable oscillation signal into a stable locked signal suitable for frequency division, resolving the stability issue while maintaining the compact magnetoresistive element design
2Device complexity
If the reference frequency is input to the frequency divider without filtering, then the circuit structure remains simple, but the PLL circuit cannot function properly and phase synchronization is not achieved
Solution Approach 1:
The filter serves as a necessary intermediary that enables the PLL circuit to function. By removing the reference frequency component before it reaches the frequency divider, the filter allows the phase comparator to properly compare phases and generate accurate phase error signals, achieving phase synchronization
Solution Approach 2:
The filter extracts and removes the harmful reference frequency component from the oscillation signal. This extraction isolates the desired high-frequency oscillation, allowing the frequency divider to process only the relevant signal components and enabling proper PLL operation
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 achieves a narrowed and sharpened oscillation spectrum, resulting in a stable frequency and enhanced channel density in communication systems.
Implementation Method 1
When a direct current is caused to flow in a direction from the free layer to the fixed layer or in a direction reverse to that direction, electron spins in the free layer are excited by a spin torque of the direct current, and the electrons are oscillated at a frequency that is unique to the free layer, so that a high-frequency wave (microwave) is oscillated
Implementation Method 2
provide a filter provided between the frequency divider and the magnetoresistive element in a region closer to the input side of the frequency divider, the filter being used for cutting off the reference frequency f ref while allowing the oscillating frequency f out to pass through the filter
Data Source
Figure 1~2
Figure 3
Figure 4(a)~4(c)
AI summary
The present invention provides a high-frequency phase-locked oscillation circuit having an extremely narrow peak width and a stable frequency so that a high-frequency wave that is oscillated by the MR element solves a problem of a large peak width of oscillation spectrum. The high-frequency phase-locked oscillation circuit is achieved by providing: a magnetoresistive element 6 that oscillates a high-frequency wave with an oscillating frequency fout; a reference signal source 1 that outputs a reference signal with a reference frequency fref; a phase-locked loop circuit having a phase comparator 3, a loop filer 4, and a frequency divider 9; an adder 5 that adds a phase error signal A output from the loop filter and a bias voltage B for oscillating the high-frequency wave from the magnetoresistive element, and that inputs an added bias voltage (A+B) to the magnetoresistive element 6; and a filter 7 provided between the frequency divider 9 and the magnetoresistive element 6 in a region closer to an input side of the frequency divider 9, the filter cutting off the reference frequency fref while allowing the oscillating frequency fout to pass through the filter.