A Review on Coupled Bulk Acoustic Wave MEMS Resonators.

Area of Science:

• Micro- and Nanosystems
• Acoustic Devices
• Resonant Systems

Background:

• Coupled resonators are key to advancing Bulk Acoustic Wave (BAW) Micro-Electro-Mechanical System (MEMS) resonators.
• BAW MEMS resonators typically operate in lateral (in-plane) or flexural (out-of-plane) vibration modes.
• Lateral modes offer higher stiffness, frequency, and Q factor with reduced internal loss and fluid damping effects.

Purpose of the Study:

• To comprehensively discuss coupled BAW MEMS resonators.
• To explore the underlying coupling theory, actuation, and sensing principles.
• To present the transduction mechanisms and diverse applications of these resonators.

Main Methods:

• Theoretical investigation of coupling principles in BAW MEMS resonators.
• Analysis of lateral and flexural vibration modes.
• Examination of transduction mechanisms for actuation and sensing.

Main Results:

• Detailed exploration of coupled BAW MEMS resonator theory.
• Comparison of lateral and flexural modes, highlighting advantages of lateral modes (higher Q factor, lower loss).
• Presentation of resonator applications in sensing, timing, and frequency reference.

Conclusions:

• Coupled BAW MEMS resonators represent a significant area of research due to their performance benefits.
• Understanding vibration modes, particularly lateral modes, is crucial for optimizing resonator design and application.
• These resonators show promise for advanced sensing, timing, and frequency reference applications.