Clock Frequency Drift Correction with In-Service Oscillator Tuning

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Solution Overview

Problem

Internal clock signals in systems like radar and radio drift over time, leading to frequency changes that can cause operational issues, and existing methods require taking the system offline for maintenance to adjust the clock signal source.

Innovation Solution

A method and apparatus that monitor the frequency of the clock signal source, compare it to a predetermined range, and adjust the control signal to a voltage-controlled oscillator using a voltage regulator, allowing for incremental changes to maintain the frequency within the specified range without requiring system downtime, utilizing a processing unit and circuit to determine if and how to adjust the frequency based on the system's current state.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the clock signal source frequency is adjusted using traditional methods, then the frequency can be corrected, but the system must be taken offline for maintenance

Engineering Contradiction:
Improvesystem continuityVSAvoidfrequency adjustment operation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system performs self-diagnosis and self-adjustment of the clock signal source frequency. The processing unit automatically detects frequency drift and adjusts the control signal without requiring external intervention or system shutdown, enabling the system to service itself while maintaining operational continuity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system implements a closed-loop feedback mechanism where the frequency of the clock signal source is continuously monitored, compared against the operating range, and used to automatically adjust the control signal. This feedback loop enables real-time frequency correction without interrupting system operation.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If the system continuously monitors and adjusts clock frequency, then frequency accuracy is maintained, but processing resources are consumed

Engineering Contradiction:
Improvefrequency measurement accuracyVSAvoidprocessing resource usage
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The system performs frequency monitoring and adjustment only when necessary - specifically when frequency drift is detected outside the operating range. Rather than continuously adjusting, the system applies corrective action only when needed, reducing unnecessary processing resource consumption while maintaining frequency accuracy.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The system implements periodic frequency checking and adjustment cycles. The processing unit monitors frequency at intervals and performs adjustments only when drift is detected, rather than continuously, thereby balancing measurement precision with resource efficiency.

Inventive Principle:
Principle #19Periodic action

3Reliability

If the clock signal source frequency drifts over time, then operational issues occur, but frequent adjustments increase system complexity

Engineering Contradiction:
Improveoperational reliabilityVSAvoidfrequency control system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The processing unit performs multiple functions: it monitors system operation state, measures clock frequency, determines whether adjustment is needed, and executes the adjustment. By consolidating these functions into a single multi-functional component, the system maintains operational reliability without proportionally increasing overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

This approach allows for efficient and fast maintenance of the clock signal source within specifications without taking the system offline, reducing resource usage and minimizing operational disruptions by dynamically adjusting the frequency as needed.

Implementation Method 1

the clock signal source comprises a voltage regulator coupled to a voltage controlled oscillator, and wherein modifying the control signal provided to the clock signal source comprises: changing the control signal by one of the first or second predetermined values, wherein the first predetermined value causes an increase in an output of the voltage regulator by a first predetermined incrementing value and the second predetermined value causes a decrease in the output of the voltage regulator by a second predetermined decrementing value

Methodology Applied
Scientific EffectVoltage control:

Data Source

PatentEP3652607B1Clock frequency control system
Publication Date: 2021.04.21 RAYTHEON CO
  • EP3652607B1 patent drawingFigure 1
  • EP3652607B1 patent drawingFigure 2
  • EP3652607B1 patent drawingFigure 3~4

AI summary

The frequency of a clock signal is compared to a predetermined range. If the measured frequency is outside the range, a system controller determines if a current operating state of the overall system allows for the internal clock to be adjusted back into compliance. If the controller determines that the current system state allows for the change, then a control signal to the internal clock signal source is changed by the smallest increment available, either to increase or decrease the frequency. If the internal clock signal is out of the desired range, and the system controller does not decide to modify the frequency, the controller may increase the size of the range by decreasing the lower bound and/or increasing the upper bound.