Through-Holes Design for Ideal LiNbO₃ A1 Resonators

Area of Science:

• Materials Science
• Electrical Engineering
• Acoustic Devices

Background:

• Lithium niobate (LiNbO3) is a key material for advanced electronic devices.
• Existing LiNbO3 resonators suffer from spurious modes, limiting performance.
• Improving resonator stability and design flexibility is crucial for practical applications.

Purpose of the Study:

• To propose and validate a method for realizing ideal LiNbO3 A1 resonators.
• To suppress all unfavorable spurious modes in LiNbO3 resonators.
• To enhance the overall performance and applicability of LiNbO3-based filters.

Main Methods:

• Introducing subwavelength through-holes between interdigital transducer (IDT) electrodes on the LiNbO3 surface.
• This method is compatible with various IDT electrode parameters and LiNbO3 thicknesses.
• The technique requires no additional fabrication steps.

Main Results:

• Complete suppression of all unfavorable spurious modes in LiNbO3 A1 resonators.
• Significant reduction in the suspended area of the LiNbO3 thin film.
• Enhanced design flexibility, compactness, mechanical and temperature stability, and power tolerance.

Conclusions:

• The proposed through-hole method effectively realizes ideal LiNbO3 A1 resonators.
• This technique offers substantial improvements in resonator characteristics.
• It is expected to significantly advance the practical application of LiNbO3 A1 filters and Lamb wave filters.