Patent ID: 7956705

Claim:
A circuit for use with bulk acoustic waves, the circuit comprising: a first electroacoustic system in a first branch; a second electroacoustic system in a second branch; wherein the first electroacoustic system comprises a first resonator and a second resonator that are in series in the first branch, that are galvanically separated, and that are acoustically coupled by a first coupling system; wherein the second electroacoustic system comprises a first resonator and a second resonator that are connected in series in the second branch, that are galvanically separated, and that are acoustically coupled by a second coupling system; wherein the first and second electroacoustic systems are acoustically coupled via the first and second coupling systems and/or are electrically coupled; and a first electric port and a second electric port, wherein at least one of the first and second electric ports is symmetrically interconnected; wherein a first signal path is between first terminals of the first and second electric ports; wherein a second signal path is between second terminals of the first and second electric ports; wherein the first branch corresponds to the first signal path and the second branch corresponds to the second signal path; wherein the second terminal of the first electric port is electrically connected to a first reference potential; wherein the second resonator of the first electroacoustic system is between the first terminal of the second electric port and a second reference potential; and wherein the second resonator of the second electroacoustic system is between the second terminal of the second electric port and a third reference potential.