Network Analyzer Measurement Uncertainty Display

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Solution Overview

Problem

Determining measurement uncertainty in vector network analyzers is complex due to numerous influencing variables, requiring extensive user input and interpretation of measurement uncertainty curves, which is difficult even for experienced technicians, especially for non-linear measurement objects where system error correction and calibration are challenging.

Innovation Solution

The method calculates measurement uncertainty automatically within the network analyzer's internal computer using pre-stored data in databases, eliminating the need for user interaction by accessing manufacturer-provided databases for device settings, calibration standards, and effective system data, and displaying uncertainty directly with measurement curves.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If measurement uncertainty is calculated using known methods with multiple influencing variables, then measurement precision is improved, but device complexity and ease of operation deteriorate due to extensive user input requirements

Engineering Contradiction:
Improvemeasurement uncertainty determinationVSAvoiduser input and interpretation
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent applies preliminary action by pre-calculating and storing measurement uncertainty data in databases during the manufacturing process. The network analyzer is pre-configured with calibration data, error correction coefficients, and uncertainty characteristics for various measurement conditions. This eliminates the need for users to perform complex calculations during operation, as the system automatically retrieves and applies the pre-computed uncertainty values based on current measurement parameters.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements self-service by automatically determining measurement uncertainty without requiring user intervention. The internal computer automatically selects appropriate uncertainty curves from databases based on measurement frequency and type, performs necessary conversions between linear and dB scales, and displays the uncertainty directly on measurement results. This automation makes the system serve itself rather than requiring expert user input.

Inventive Principle:
Principle #25Self-service

2Measurement precision

If measurement uncertainty curves are provided separately for amplitude and phase, then measurement precision is improved, but device complexity increases requiring offset calculations

Engineering Contradiction:
Improveseparate amplitude and phase uncertaintyVSAvoidtolerance region calculation
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the separate amplitude and phase uncertainty representations into a unified complex uncertainty display. Instead of requiring users to manually offset amplitude and phase tolerance curves against each other, the system combines these into a single visual representation showing the complete uncertainty region in the complex plane. This integration maintains the precision benefits of separate measurements while eliminating the complexity of manual combination.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system transitions from displaying uncertainty as separate 1D curves for amplitude and phase to a 2D complex plane representation. This dimensional change allows both amplitude and phase uncertainties to be visualized simultaneously in their proper geometric relationship, showing the uncertainty as a region rather than separate lines. This resolves the complexity of offset calculations by providing an intuitive visual overlay in the complex domain.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Device complexity

If linear scales are used for display, then device complexity is reduced, but measurement precision deteriorates due to scale mismatch with dB scale

Engineering Contradiction:
Improvedisplay scaleVSAvoidtolerance representation
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent implements dynamic scaling that automatically adapts to the measurement scale being used. When the user displays measurements in dB scale, the uncertainty representation automatically converts to dB scale as well, maintaining proper scaling correspondence. This dynamic adaptation ensures that tolerance regions are always displayed in the correct scale without requiring manual intervention or complex fixed-scale workarounds.

Inventive Principle:
Principle #15Dynamics

4Measurement precision

If extensive user input is required for uncertainty calculation, then measurement precision is improved, but productivity deteriorates

Engineering Contradiction:
Improveuncertainty calculation accuracyVSAvoidmeasurement throughput
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The system uses preliminary action by pre-computing uncertainty values for all standard measurement conditions during manufacturing and storing them in databases. This allows the measurement process to proceed rapidly without requiring users to perform time-consuming uncertainty calculations, while still maintaining high precision through the use of pre-calibrated, factory-determined uncertainty data.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP1987364B1Method for representation of measurement results of a network analyser with simultaneous tolerance display
Publication Date: 2019.04.10 ROHDE & SCHWARZ GMBH & CO KG
  • EP1987364B1 patent drawingFigure 1
  • EP1987364B1 patent drawingFigure 2~4
  • EP1987364B1 patent drawingFigure 5~7

AI summary

According to the invention, the measurement uncertainty of measured values from a network analyser are determined by directly calculating the measurement uncertainty by amount and/or phase in conventional manner in the internal computer of the network analyser for each measured value and displaying the same with the corresponding measured value. All data necessary for the calculation, arising directly from the properties and operation of the network analyser, are stored in the data bank provided for the internal computer such as to be directly accessible for said internal computer. Only that data from applied additional measuring means which are different from data already stored in the data bank are inputted to the data bank by the user and calculated there with the original data and taken into account as novel data on calculation of measurement uncertainty.