Topological Optimization of Circular SAW Resonators: Overcoming the Discreteness Effects

Area of Science:

• Materials Science and Engineering
• Electrical Engineering
• Acoustics and Wave Phenomena

Background:

• Surface Acoustic Wave (SAW) resonators are crucial for various sensing applications.
• Previous work introduced a ring-shaped SAW resonator design focusing on temperature stability.
• Existing designs require further optimization for enhanced signal detection and manufacturing robustness.

Purpose of the Study:

• To further optimize the ring-shaped SAW resonator design for narrower bandwidth and improved signal detection.
• To assess the design's operability under typical lithography-induced defects.
• To investigate structural alterations of the interdigital transducer (IDT) for enhanced performance and defect tolerance.

Main Methods:

• Utilized COMSOL Multiphysics for computer simulations of various IDT configurations.
• Proposed and simulated a partially fragmented interdigital transducer (IDT) design.
• Analyzed the impact of IDT pin geometry variations on resonator performance.

Main Results:

• Demonstrated that structural alteration of the IDT, specifically partial fragmentation, can optimize resonator performance.
• Validated several IDT options through simulations, showing explicit improvements via pin geometry changes.
• Confirmed the potential for improved signal detection and bandwidth narrowing.

Conclusions:

• The optimized ring-shaped SAW resonator design, featuring a modified IDT, shows promise for enhanced signal detection and robustness against lithography defects.
• The proposed IDT fragmentation strategy is effective in improving resonator operability under manufacturing variations.
• Results support proceeding with prototyping and fabrication of the optimized resonators using photolithography.