Oscillator Holdover Control for Accurate Reference Frequency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing reference frequency generating devices struggle to maintain highly accurate output when the reference signal is unavailable, particularly during rapid temperature changes, as they rely solely on elapsed time and temperature variations for holdover control.
Innovation Solution
A reference frequency generating device incorporating a synchronization circuit, temperature detector, and controller that corrects voltage-controlled signals based on the aging characteristic of the oscillator, using a temperature approximating function and second-order differentiation to generate a holdover control signal, considering changes in the temperature slope and thermal shock effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If only elapsed time and temperature changes are used for holdover control, then the control method remains simple, but the frequency accuracy deteriorates during rapid temperature changes
Solution Approach 1:
The system performs preliminary actions by detecting temperature changes in advance and calculating correction amounts based on pre-stored aging characteristic data. The controller proactively adjusts the voltage-controlled signal before frequency deviation occurs, using the temperature detector to monitor temperature and retrieve appropriate correction values from storage, thereby maintaining frequency accuracy without complex real-time calculations
Solution Approach 2:
The patent replaces complex mechanical frequency stabilization mechanisms with an electronic correction system. Instead of using intricate mechanical feedback loops, the system uses a temperature detector, storage device, and controller that electronically retrieve and apply correction amounts based on temperature-slope information, substituting mechanical complexity with electronic data processing
2Reliability
If the oscillator temperature shifts rapidly from changing state to stable state, then thermal shock occurs causing aging characteristic changes, but conventional control cannot detect this state transition, leading to frequency deviation
Solution Approach 1:
The system implements feedback by continuously monitoring temperature through the temperature detector and using this information to adjust the voltage-controlled signal. The controller receives temperature data, determines temperature slope states, and applies appropriate correction amounts from storage, creating a closed-loop feedback system that automatically responds to temperature changes and maintains frequency accuracy during holdover control
Solution Approach 2:
The patent applies parameter changes by utilizing the temperature slope as a key parameter to determine correction amounts. The system changes the correction strategy based on the temperature slope state (rapid change vs. stable), retrieving different correction values from storage corresponding to different temperature conditions, thereby adapting the holdover control to match the current thermal state of the oscillator
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 enables continuous output of highly accurate reference frequency signals even in holdover states by accurately detecting and correcting for aging characteristic changes, ensuring frequency stability despite rapid temperature shifts.
Implementation Method 1
a temperature detector that detects a temperature of the oscillator being used
Data Source
AI summary
To provide a reference frequency generating device that can output a highly accurate reference frequency signal even if a reference signal becomes unable to be acquired. The reference frequency generating device includes a synchronization circuit, a temperature sensor, and a controller. The synchronization circuit controls a reference frequency signal outputted from a voltage controlled oscillator, by a control signal obtained based on a reference signal. The temperature detector detects a temperature of the voltage controlled oscillator being used. When the reference signal is unable to be acquired, the controller corrects a voltage controlled signal in consideration of a distortion in the aging characteristic of the voltage controlled oscillator based on a rate of change with time in a slope of the oscillator temperature, and generates a holdover control signal based on corrected contents to control the voltage controlled oscillator.