TWO-WAY PIEZOELECTRIC MEMS MICROSPEAKER WITH NOVEL STRUCTURE AND ELECTRODE DESIGN FOR BANDWIDTH ENHANCEMENT

This study presents a piezoelectric MEMS tweeter with novel structure and electrodes designs (Fig.1) for two-way excitation to enlarge its bandwidth, which can meet the requirement of in-ear applications. The proposed design has two merits: (1) Dual-ring spring design: to offer two resonant modes with piston vibrations to contribute sound pressure, (2) Distribution and excitation of driving electrodes design: to achieve the two-way excitation to drive the two required vibration modes. Thus, this proposed design could enlarge the bandwidth at the high frequency range with decent sound pressure level (SPL). Measurements in the standard ear simulator with 2Vpp input voltage demonstrate the presented tweeter has a significant bandwidth improvement of 14 kHz similar to 30 kHz (for the +/- 10dB range of SPL (72 dB SPL similar to 92 dB SPL)).

Automated summary

This study presents a novel design of piezoelectric MEMS tweeter with two-way excitation to enlarge bandwidth for in-ear applications. The design features a dual-ring spring design and driving electrodes design to achieve bandwidth extension and increase in sound pressure level.