摘要
This study presents a novel piezoelectric MEMS microspeaker consisted of cantilever membranes and low-pass filter to enhance bandwidth (Fig.1). Features of the design: (1) monolithic integration with microspeaker and low-pass filter: to reduce the power consumption and to eliminate SPL zeros w/o external circuits, (2) the low-pass filter supports the gain-modulation driving method. Moreover, the design also easily modulates the 1st and 2nd resonances by shifting the cantilever anchors under the same area. Thus, large dynamic responses are achieved from the cantilevers to maintain SPL performance and further expanded the bandwidth by using a low-pass filter. Measurements show the design has full-range (2.7kHz similar to 17kHz) 75dB bandwidth under 0.707V(rms)+6V(DC) driving voltage in standard ear simulator (Table1).