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Updated: Jun 10, 2026
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Terahertz Microfluidic Sensing Using a Parallel-plate Waveguide Sensor
Published on: August 30, 2012
Ultrasonic waveguide with square wave surface grating
Omar R Asfar1, Mohmmed H Bataineh, Muhammad A Hawwa
1Electrical Engineering Department, Jordan University of Science & Technology, Irbid, Jordan.
Summary
Spatial harmonics in surface gratings create stopbands for ultrasonic SH waves in elastic plates. These stopbands, influenced by Bragg resonances and mode coupling, are crucial for wave manipulation.
Area of Science:
- Acoustics
- Solid Mechanics
- Materials Science
Background:
- Surface gratings on elastic plates can modify wave propagation.
- Understanding multiband frequency responses is key for ultrasonic applications.
Purpose of the Study:
- Investigate the impact of spatial harmonics in square-wave gratings on ultrasonic SH wave propagation.
- Analyze the formation and characteristics of stopbands in elastic plates.
Main Methods:
- Utilized the multiple scales scheme for theoretical analysis.
- Derived coupled mode equations.
- Solved numerically using the fundamental matrix method.
Main Results:
- Identified stopbands arising from combined Bragg resonances and mode coupling.
- Observed stopbands appearing above cutoff frequencies of odd-numbered modes due to the grating's odd harmonic nature.
- Found maximum attenuation when all propagating modes are coupled and reflected.
Conclusions:
- Spatial harmonics significantly influence ultrasonic SH wave propagation in elastic plates.
- The study provides insights into designing structures for controlled wave attenuation.
- Conditions for higher-order stopbands require at least one co-directional mode coupling.
