High coupling, low loss PBAW device and associated method

摘要

In embodiments, a piezoelectric acoustic wave (PBAW) device may include a substrate and a resonator comprising a plurality of electrodes coupled with the surface of the substrate. A dielectric overcoat may be disposed over the substrate and the resonator. In embodiments, and electrode in the resonator electrode may have a width that is based at least in part on a period of the resonator. By selecting the width of the electrode based at least in part on the period of the resonator, a spurious-mode of the passband of the PBAW device may be suppressed.

主权项

1. A piezoelectric boundary acoustic wave (PBAW) device comprising:
a substrate; a resonator coupled with a surface of the substrate, the resonator comprising a plurality of electrodes having a period and an electrode in the plurality of electrodes having a width based at least in part on a period of the electrode where electrodes in the plurality of electrodes have a height based at least in part on a density measurement of a material of the electrodes and a shear modulus of the material of the electrodes, wherein the height of the electrodes is equal to(cmcox)4(ΔmΔox-1)>hm>0.5*(cmcox)4(ΔmΔox-1)where hm is the height of the electrodes, cm is a shear modulus of the electrodes, cox is a shear modulus of the dielectric overcoat, Δm is a density of the electrodes, and Δox is a density of the dielectric overcoat;
a dielectric overcoat coupled with the substrate and the resonator, the dielectric overcoat disposed over the substrate and the resonator, the dielectric overcoat having a shear wave velocity; andan additional material coupled with a surface of the dielectric overcoat, the additional material having a shear wave velocity that is greater than the shear wave velocity of the dielectric overcoat.