| 摘要 |
<p>A bulk acoustic wave device has a number of resonator elements (14) which are laterally spaced such that a signal (26) applied between to one resonator element (141) at a resonant frequency of the device is coupled to the other resonator elements (142, 143, 144) by acoustic coupling between piezoelectric layers of the resonator elements (14). There are two outer resonator elements (141, 145) and at least one inner resonator element (142, 143, 144). The terminals of the inner resonator elements are electrically connected together. This connection provides an AC short which eliminates the effect of the parasitic capacitances of the inner resonator elements, and provides electromagnetic shielding between the input and output of the device, by reducing the parasitic capacitance between the input and output upper electrodes.</p> |
