A circuit element. In some embodiments, the circuit element includes a first terminal, a second terminal, and a layered structure. The layered structure may include a first conductive layer connected to the first terminal, a first piezoelectric layer on the first conductive layer, a second piezoelectric layer on the first piezoelectric layer, and a second conductive layer connected to the second terminal. The first piezoelectric layer may have a first piezoelectric tensor and a first permittivity tensor, and the second piezoelectric layer may have a second piezoelectric tensor and a second permittivity tensor, one or both of the second piezoelectric tensor and a second permittivity tensor differing, respectively, from the first piezoelectric tensor and the first permittivity tensor.