Virtual AC Impedance Measurement for Semiconductor Gas Sensors

Solution Overview

Problem

Semiconductor gas sensors face challenges with high hardware cost and complex systems due to the complexity and expense of alternating current impedance measurement methods, which are more complicated than direct current measurement.

Innovation Solution

A method for measuring semiconductor gas sensors using virtual alternating current impedance, replacing alternating current measurement with direct current measurement while maintaining high output linearity and baseline stability, by calculating virtual impedance characteristic quantities and selecting optimal measurement parameters based on linearity and signal-to-noise ratios.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If alternating current impedance measurement method is used, then output linearity and baseline stability are improved, but hardware cost and system complexity increase

Engineering Contradiction:

Improvebaseline stabilityVSAvoidsystem complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent creates a virtual copy of the alternating current impedance measurement system by calculating equivalent impedance values from direct current measurements. Instead of physically implementing complex AC measurement circuits, the invention computes virtual impedance characteristics (real and imaginary components) that replicate AC measurement outcomes, thereby achieving AC measurement benefits with DC measurement simplicity

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent replaces the physical alternating current measurement system with a computational model. By substituting the mechanical/electrical AC measurement apparatus with mathematical calculations based on DC resistance measurements, the invention eliminates the need for complex hardware while maintaining measurement accuracy and reliability

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If alternating current impedance measurement method is used, then output linearity is improved, but hardware cost increases

Engineering Contradiction:

Improveoutput linearityVSAvoidhardware cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent creates a virtual copy of the alternating current impedance measurement system by calculating equivalent impedance values from direct current measurements. Instead of physically implementing complex AC measurement circuits, the invention computes virtual impedance characteristics (real and imaginary components) that replicate AC measurement outcomes, thereby achieving AC measurement benefits with DC measurement simplicity

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent employs inexpensive direct current measurement equipment instead of costly alternating current impedance measurement hardware. By using simple DC voltmeters and ammeters to gather data that is then processed through virtual impedance calculations, the invention achieves high output linearity with minimal hardware investment

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Measurement precision

If alternating current measurement is used, then measurement accuracy is improved, but system complexity increases

Engineering Contradiction:

Improvemeasurement accuracyVSAvoidsystem complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent creates a virtual copy of the alternating current impedance measurement system by calculating equivalent impedance values from direct current measurements. Instead of physically implementing complex AC measurement circuits, the invention computes virtual impedance characteristics (real and imaginary components) that replicate AC measurement outcomes, thereby achieving AC measurement benefits with DC measurement simplicity

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent divides the measurement process into distinct segments: first performing simple DC resistance measurements, then separately calculating the real and imaginary components of impedance through mathematical operations. This segmentation allows complex AC measurement tasks to be broken down into manageable DC measurement steps followed by computational processing

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS11635403B2Method for measuring semiconductor gas sensor based on virtual alternating current impedance

Publication Date: 2023.04.25 XI AN JIAOTONG UNIV

AI summary

The invention discloses a method for measuring a semiconductor gas sensor based on virtual alternating current impedance. The method comprises: combining measurement parameters of virtual measurement frequencies in a first predetermined range and virtual parallel capacitance values in a second predetermined range, and measuring gas with known concentrations at each characteristic quantity among nine characteristic quantities in the case of each combination; obtaining multiple characteristic values corresponding to the same gas concentration at each characteristic quantity after traversing all parameter combinations and all nine characteristic quantities; and selecting virtual measurement frequencies in a third range, virtual parallel capacitance values in a fourth range and one or several corresponding characteristic quantities as the finally selected measurement parameters for measuring the unknown gas concentration.