A 4th-order band-pass filter using differential readout of two in-phase actuated contour-mode resonators

作者：Yagubizade Hadi^*; Darvishi Milad; Elwenspoek Miko C; Tas Niels R

来源：Applied Physics Letters, 2013, 103(17): 173517.

DOI：10.1063/1.4826944

A 4th-order band-pass filter (BPF) based on the subtraction of two 2nd-order contour-mode Lamb-wave resonators is presented. The resonators have slightly different resonance frequencies around 380 MHz. Each resonator consists of a 500 nm pulsed-laser deposited lead zirconate titanate (PZT) thin-film on top of a 3 mu m silicon (PZT-on-Si). The resonators are actuated in-phase, and their outputs are subtracted. Utilizing this technique, the feed-through signals are eliminated while the outputs of the resonators are added up constructively, due to the phase difference between the two output signals. The BPF is presented using 50 Omega termination with a bandwidth of approximately 3.9 MHz and 43 dB stopband rejection. This technique provides further opportunities for MEMS filter design in addition to existing methods, i.e., mechanical and/or electrical coupling. It also resolves the design issue associated with high feed-through when exploiting piezoelectric materials with high-dielectric constant like PZT.

• 出版日期2013-10-21