Title

Development of a Compact SAW Sensor System Employing Multiple Resonance Modes for Environmental Monitoring

Alternative Title

복수의 공진 모드를 활용한 소형 SAW 센서 시스템의 개발 및 환경 모니터링 응용

DGIST Authors

Mingyu Seo ; Hoe Joon Kim

Advisor

김회준

Issued Date

2026

Awarded Date

2026-02-01

Type

Thesis

Description

Surface acoustic wave, SAW filter, SAW sensor system, Quartz, Lithium niobate, Finite element analysis, COMSOL

Table Of Contents

List of Contents
Abstract i
List of contents ii
List of tables iii
List of figures vi

Chapter 1. Introduction 1
1.1 Background and Motivation 1
1.2 Research Objective and Approach 2
1.3 Thesis Outline and Contributions 3

Chapter 2. High-Performance Dual-Mode SAW Sensor on X-Cut LiNbO3 for Real-Time Temperature and Humidity Sensing with Self-Decoupling Capability 4
2.1 Abstract 4
2.2 Introduction 5
2.3 Materials and Methods 7
2.3.1 Fabrication of the SAW resonator 7
2.3.2 Electrospray deposition and characterization of graphene oxide 7
2.3.3 Experimental setup 7
2.4 Results and Discussion 9
2.4.1 Characterization of Rayleigh and SH modes in X-cut LiNbO3 using FEA 10
2.4.2 Comparison of propagation behavior between two wave modes using FEA · 11
2.4.3 Characterization of fabricated SAW sensor 14
2.4.4 Comparative analysis of humidity sensing performance 17
2.4.5 Temperature sensing performance of Rayleigh and SH modes 20
2.4.6 Decoupling of temperature and humidity responses via dual resonance modes21
2.5 Conclusion 24

Chapter 3. Design of a Dual-Mode ST-Cut Quartz SAW Resonator with Integrated Oscillator Circuit for a Multi-Parameter Sensing System 25
3.1 Abstract 25
3.2 Introduction 26
3.3 Materials and Methods 28
3.3.1 Simulation of resonance mode on ST-cut quartz 28
3.3.2 Fabrication of two port SAW resonator 29
3.3.3 Design of a closed-loop oscillator circuit for test 29
3.4 Results and Discussion 31
3.4.1 Design parameter effect of two-port SAW resonator 31
3.4.2 Test and validation of SAW oscillator for sensing system 33
3.4.3 Design of a dual-mode SAW oscillator circuit 34
3.5 Conclusion and Future Work 35

Chapter 4. Conclusion and Future Work 36
4.1 Conclusion 36
4.2 Future work 37

References 38
요약문 42
Appendix: Fabrication Process of LiNbO3 and Quartz based Resonator 43

URI

https://scholar.dgist.ac.kr/handle/20.500.11750/59671
http://dgist.dcollection.net/common/orgView/200000947176

DOI

10.22677/THESIS.200000947176

Degree

Master

Department

Department of Robotics and Mechatronics Engineering

Publisher

DGIST

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