Patent ID: 8674789
Filing Date: 2014-03-18
Classification: H03H

Abstract:
1. An acoustic device, comprising: a first coupled resonator filter (CRF) and a second CRF electrically coupled to one another, wherein each of the first CRF and the second CRF has an input port, an output port, a bottom film bulk acoustic resonator (FBAR), an acoustic decoupler formed on the bottom FBAR, and a top FBAR formed on the acoustic decoupler, wherein each of the bottom FBAR and the top FBAR has a bottom electrode, a piezoelectric layer formed on the bottom electrode, and a top electrode formed on the piezoelectric layer, and wherein for each CRF, the input port is electrically connected to the bottom electrode or the top electrode of the top FBAR and the output port is electrically connected to the top electrode or the bottom electrode of the bottom FBAR, or vice versa, such that the acoustic decoupler is located between the input port and the output port, wherein the output port of the first CRF is electrically connected to the input port of the second CRF; and wherein at least one of the first CRF and the second CRF has a respective feedback capacitor defined between the corresponding input and output ports of the at least one of the first CRF and the second CRF.