Spurious Frequency Attenuation Servo for Automatic Spur Cancellation

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Solution Overview

Problem

Existing frequency generators suffer from distortion due to nonlinearity, causing spurious frequencies that require manual adjustment of phase and amplitude to cancel, which is time-consuming and inefficient as system parameters change over time.

Innovation Solution

A spurious frequency attenuation servo system that automatically generates a cancellation signal with opposite polarity and adjusts to cancel unwanted spurious frequencies, using a combination of function generators, mixers, error accumulators, and multipliers to form an output signal that eliminates spurious frequencies without manual user intervention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If manual adjustment of phase and amplitude is used to cancel spurs, then spur cancellation can be achieved, but the process is time-consuming and requires repeated manual adjustments as system parameters change

Engineering Contradiction:
Improveautomatic spur cancellationVSAvoidsystem complexity
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The patent implements a feedback mechanism where the system continuously monitors spurious frequencies and automatically adjusts phase and amplitude parameters to cancel them. The controller receives information about spur characteristics and dynamically modifies the cancellation signal parameters without requiring manual intervention, thus achieving automatic adaptation as system parameters change over time.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-adjustment by automatically detecting spurious frequencies and generating appropriate cancellation signals. The controller autonomously determines the required phase and amplitude adjustments and implements them without external manual operation, allowing the system to service itself as conditions change.

Inventive Principle:
Principle #25Self-service

2Productivity

If manual adjustment is used to cancel spurs, then spur reduction is possible, but productivity is reduced due to repeated manual operations

Engineering Contradiction:
Improvesystem efficiencyVSAvoidtime for manual adjustments
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The system maintains continuous operation by automatically detecting and canceling spurious frequencies without interruption. The controller continuously monitors the signal environment and adjusts cancellation parameters in real-time, eliminating the need to stop or pause operations for manual adjustments, thus maintaining uninterrupted productive operation.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The feedback loop enables real-time detection and correction of spurious frequencies, allowing the system to maintain optimal performance continuously without manual intervention. The automatic adjustment based on feedback ensures that productivity is maintained while spurs are effectively canceled.

Inventive Principle:
Principle #23Feedback

3Adaptability or versatility

If manual adjustment of phase and amplitude is performed, then spur cancellation can be achieved, but the system cannot adapt automatically as parameters change over time

Engineering Contradiction:
Improveautomatic adaptation to parameter changesVSAvoidoperational simplicity
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The feedback mechanism enables the system to automatically detect changes in spurious frequency characteristics and adjust cancellation parameters accordingly. The controller continuously monitors spur parameters and dynamically modifies the cancellation signal to maintain effectiveness as system conditions evolve, providing automatic adaptability while maintaining operational simplicity.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system transitions from static manual adjustment to dynamic automatic adjustment. The controller dynamically adapts phase and amplitude parameters in real-time based on changing system conditions, allowing the system to respond flexibly to parameter changes without requiring complex manual reconfiguration.

Inventive Principle:
Principle #15Dynamics

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 system effectively cancels spurious frequencies, maintaining signal quality by automatically adjusting to phase and magnitude shifts over time, eliminating the need for manual adjustments and ensuring consistent performance.

Implementation Method 1

an in-phase mixer configured to input the second signal and a feedback signal; a quadrature-phase mixer configured to input the third signal and the feedback signal

Methodology Applied
Scientific EffectMixing: Heterodyne

Implementation Method 2

an in-phase error accumulator configured to input the signal from the in-phase mixer; a quadrature-phase error accumulator configured to input the signal from the quadrature-phase mixer

Methodology Applied
Scientific EffectIntegration: Electrical Accumulator

Data Source

PatentEP2787410B1Spurious frequency attenuation servo
Publication Date: 2016.04.27 HONEYWELL INTERNATIONAL INC
  • EP2787410B1 patent drawingFigure 1
  • EP2787410B1 patent drawingFigure 2A~2C
  • EP2787410B1 patent drawingFigure 3

AI summary

A spurious frequency attenuation servo is provided. The spurious frequency attenuation servo includes a first function generator (20) that generates a first signal at a first frequency and at a spurious frequency; a second function generator (30) that generates a second signal in-phase with the first signal and at the spurious frequency; a third function generator (31) that generates a third signal ninety degrees out-of-phase with the first signal and at the spurious frequency; in-phase and quadrature-phase mixers (131, 141) to input a feedback signal and the second and third signals, respectively; in-phase and quadrature-phase error accumulators (132, 142); an in-phase and quadrature-phase multiplier (150, 160) to multiply an output from the in-phase and quadrature-phase error accumulators with the second and third signals, respectively; and a summing node (170) to sum the first signal with output from the in-phase and quadrature-phase multipliers to form an output signal (260, 261) that is fed back to the in-phase mixer and the quadrature-phase mixer.