A duplexer includes a piezoelectric substrate, a receiving filter formed on the piezoelectric substrate, the receiving filter includes a plurality of resonators, and a transmitting filter formed on the piezoelectric substrate, the transmitting filter includes a plurality of resonators. One of the resonators of the receiving filter is a multi-mode type acoustic wave resonator having a capacitance that is two times or more the average capacitance of the other resonators formed on the piezoelectric substrate.

A packaged acoustic wave component is disclosed. The packaged acoustic wave component can include a first acoustic wave resonator that includes a first interdigital transducer electrode that is positioned over a first piezoelectric layer. The packaged acoustic wave component can also include a second acoustic wave resonator including a second interdigital transducer electrode positioned over a second piezoelectric layer. The second piezoelectric layer is bonded to the first piezoelectric layer. The packaged acoustic wave component can further include a stopper structure that is positioned over the first piezoelectric layer. The first stopper structure is positioned above a via and extends through the first piezoelectric layer. The stopper structure is in electrical communication with the first interdigital transducer electrode and includes a material which reflects at least fifty percent of light having a wavelength of 355 nanometers.

A method includes transmitting a focused ultrasound wave into a medium to form (i) an ultrasound intensity well within the medium that exhibits a first range of acoustic pressure and (ii) a surrounding region of the medium that surrounds the ultrasound intensity well and exhibits a second range of acoustic pressure that exceeds the first range of acoustic pressure. The method further includes confining an object within the ultrasound intensity well. Additionally, an acoustic lens is configured to be acoustically coupled to an acoustic transducer. The acoustic lens has a varying longitudinal thickness that increases proportionally with respect to increasing azimuth angle of the acoustic lens. Another acoustic lens is configured to be acoustically coupled to an acoustic transducer. The acoustic lens includes a plurality of segments. Each of the plurality of segments has a varying longitudinal thickness that increases proportionally with respect to increasing azimuth angle of the segment.

A low velocity surface acoustic wave device, and a method of reducing the velocity of a surface acoustic wave generated by a surface acoustic wave device are described, the device including a piezoelectric layer, an interdigital transducer disposed on the piezoelectric substrate and configured to generate a surface acoustic wave in response to an electrical, and a temperature coefficient of frequency compensation layer disposed partially on the interdigital transducer and partially on the piezoelectric substrate, the temperature coefficient of frequency compensation layer having a low velocity layer disposed within it configured to reduce the velocity of a surface acoustic wave generated by the interdigital transducer, the method including disposing a wave velocity adjustment layer, the wave velocity adjustment layer being a low velocity layer, within a temperature compensation layer of the surface acoustic wave device.

A filter circuit includes a plurality of first resonators provided in a series arm, a plurality of second resonators provided in a parallel arm, and at least one or more third resonators that are electrically connected in series with each other and are electrically connected in parallel with the first resonators in the series arm. An anti-resonant frequency of the third resonators is lower than an anti-resonant frequency of the second resonators. A combined capacitance of the at least one or more third resonators electrically connected in series with each other is smaller than an electrostatic capacitance of the second resonators.

A filter circuit includes a plurality of first resonators provided in a series arm, a plurality of second resonators provided in a parallel arm, and at least one or more third resonators that are electrically connected in series with each other and are electrically connected in parallel with the first resonators in the series arm. An anti-resonant frequency of the third resonators is lower than an anti-resonant frequency of the second resonators. A combined capacitance of the at least one or more third resonators electrically connected in series with each other is smaller than an electrostatic capacitance of the second resonators.

A bulk acoustic resonator architecture is fabricated by epitaxially forming a piezoelectric film on a top surface of post formed from an underlying substrate. In some cases, the acoustic resonator is fabricated to filter multiple frequencies. In some such cases, the resonator device includes two different resonator structures on a single substrate, each resonator structure configured to filter a desired frequency. Including two different acoustic resonators in a single RF acoustic resonator device enables that single device to filter two different frequencies in a relatively small footprint.

A filter module includes an inductor, a filter including first wiring, and second wiring between the inductor and the first wiring and being a direct-current floating potential. The inductor and the first wiring are magnetically coupled, the inductor and the second wiring are magnetically coupled, and the first wiring and the second wiring are capacitively coupled.

A filter circuit that secures the steepness from a pass range to an attenuation range while maintaining a wide-band transmission characteristic and a filter device including this filter circuit are formed. A filter circuit includes a first filter and a second filter. The first filter is a filter including an LC circuit in which a first frequency band is a pass band and a frequency band not higher than the first frequency band is an attenuation band. The second filter is a filter that attenuates a second frequency band within the first frequency band by using an attenuation pole produced by a resonance or an antiresonance of an acoustic wave resonator. Further, the first filter is placed closer to an antenna terminal than the second filter.

Embodiments of resonator circuits and modulating resonators and are described generally herein. One or more acoustic wave resonators may be coupled in series or parallel to generate tunable filters. One or more acoustic wave resonances may be modulated by one or more capacitors or tunable capacitors. One or more acoustic wave modules may also be switchable in a filter. Other embodiments may be described and claimed.