Oscillator Temperature Compensation Using Resonator Group Delay

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Solution Overview

Problem

Conventional temperature compensation circuits for oscillators either consume high power with higher frequency stability or exhibit measurement errors with lower power consumption, failing to balance frequency stability and power efficiency effectively.

Innovation Solution

A circuit design incorporating a resonator group-delay analyzer and a second resonator to determine group-delay amplitude, which provides a control signal to adjust the oscillator frequency, thereby compensating for temperature-induced frequency variations while optimizing power consumption and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If frequency detection approach is used for temperature compensation, then frequency stability is improved, but power consumption increases

Engineering Contradiction:

Improvefrequency stabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent replaces the conventional frequency detection circuit with a time-domain measurement approach using group-delay analysis. Instead of measuring frequency directly (which requires complex phase-locked loops and high power), the system measures the group delay of the resonator in the time domain, which can be done with simpler, lower-power circuitry while achieving comparable or better temperature compensation accuracy.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the measurement parameter from frequency domain to time domain. By measuring group delay (a time-domain parameter) instead of frequency directly, the system achieves temperature compensation with reduced power consumption. The group delay measurement provides sufficient temperature information without requiring the high-power frequency detection mechanisms.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If frequency detection approach is used for temperature compensation, then frequency stability is improved, but response time increases

Engineering Contradiction:

Improvefrequency stabilityVSAvoidresponse time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent substitutes the slow frequency detection mechanism with a faster time-domain group delay measurement system. The group delay can be measured more quickly than traditional frequency stabilization methods, reducing the response time while maintaining frequency stability through the same temperature compensation objective.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Use of energy by moving object

If constant resistance approach is used for temperature compensation, then power consumption is reduced, but measurement error increases

Engineering Contradiction:

Improvepower consumptionVSAvoidmeasurement error

Core Design Contradiction:

Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The patent replaces the simple but inaccurate constant resistance voltage measurement with a time-domain group delay measurement approach. This substitution maintains low power consumption characteristics while significantly improving measurement precision, as group delay provides more accurate temperature information than voltage across a resistor.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 effectively stabilizes oscillator frequencies by adjusting for temperature variations with reduced power consumption and improved accuracy, balancing the trade-offs of conventional methods.

Implementation Method 1

the temperature compensation circuit includes a resonator group-delay analyzer and a second resonator, the resonator group-delay analyzer having first and second analyzer inputs and an analyzer output

Methodology Applied

Scientific EffectGroup-delay analysis:

Implementation Method 2

The oscillator control circuitry is configured to adjust a frequency of an output signal at the oscillator output responsive to the control signal

Methodology Applied

Scientific EffectFrequency adjustment:

Implementation Method 3

By increasing the resonance frequency of the electroacoustic resonator over the oscillation frequency, the oscillator short-term instability becomes less dependent on the resonator quality factor

Methodology Applied

Scientific EffectResonance: Resonance

Data Source

PatentUS20240146309A1Oscillator circuit having temperature compensation based on resonator group-delay analysis

Publication Date: 2024.05.02 TEXAS INSTRUMENTS INC

AI summary

A circuit includes: a first resonator; a temperature compensation circuit including a resonator group-delay analyzer and a second resonator; oscillator control circuitry; and a controller. The resonator group-delay analyzer is configured to determine a group-delay parameter responsive to operations of the second resonator. The controller is configured to provide a control signal responsive to the group-delay parameter. The oscillator control circuitry is configured to adjust a frequency of an output signal of the oscillator control circuitry responsive to the control signal.