A bulk-acoustic wave filter device includes: a lower electrode layer disposed on the substrate; a bonding part disposed on the lower electrode layer, at an edge of the substrate; a ground part spaced apart from the bonding part; and a flow suppressing part disposed between the bonding part and the ground part, and offset with respect to the bonding part and the ground part.

A method and structure for a transfer process for an acoustic resonator device. In an example, a bulk acoustic wave resonator (BAWR) with an air reflection cavity is formed. A piezoelectric thin film is grown on a crystalline substrate. A first patterned electrode is deposited on the surface of the piezoelectric film. An etched sacrificial layer is deposited over the first electrode and a planarized support layer is deposited over the sacrificial layer, which is then bonded to a substrate wafer. The crystalline substrate is removed and a second patterned electrode is deposited over a second surface of the film. The sacrificial layer is etched to release the air reflection cavity. Also, a cavity can instead be etched into the support layer prior to bonding with the substrate wafer. Alternatively, a reflector structure can be deposited on the first electrode, replacing the cavity.

The invention relates to an acoustically coupled thin-film BAW filter, comprising a piezoelectric layer, an input-port on the piezoelectric layer changing electrical signal into an acoustic wave (SAW, BAW), and an output-port on the piezoelectric layer changing acoustic signal into electrical signal. In accordance with the invention the ports include electrodes positioned close to each other, and the filter is designed to operate in first order thickness-extensional TE1 mode.

A high frequency circuit includes a first demultiplexing circuit including a first high pass filter and a low pass filter and a second demultiplexing circuit including a band elimination filter and a band pass filter, the second demultiplexing circuit being connected in series with the first demultiplexing circuit. At least one of the band elimination filter and the band pass filter includes an elastic wave resonator. An attenuation band of the band elimination filter and a pass band of the band pass filter is located between a pass band of the first high pass filter and a pass band of the low pass filter.

A cancellation-based filter may have at least one frequency pass band and at least one frequency stop band. The cancellation-based filter may include a first group of one or more band pass filters, each having at least one acoustic resonator, the first group providing at least one frequency pass band for the cancellation-based filter; at least one hybrid coupler; and a second group of one or more band pass filters, each having at least one acoustic resonator, the second group coupled to at least one of the at least one hybrid couplers, wherein the at least one hybrid coupler and the second group of one or more band pass filters interact to provide at least one frequency stop band for the cancellation-based filter.

Reversed semilattice filters with improved common mode rejection characteristics are disclosed. In one aspect, a filter may include two interior nodes coupled with an impedance that treats unwanted signals as common mode signals and provides rejection for common mode signals while passing differential signals of interest. The impedance is modified to have a resonant circuit that improves signal rejection in the stop band by lowering the effective impedance at those frequencies while leaving the pass band unaffected.

The invention relates to an acoustically coupled thin-film BAW filter, comprising a piezoelectric layer, an input-port on the piezoelectric layer changing electrical signal into an acoustic wave (SAW, BAW), and an output-port on the piezoelectric layer changing acoustic signal into electrical signal. In accordance with the invention the ports include electrodes positioned close to each other, and the filter is designed to operate in first order thickness-extensional TE1 mode.

A laterally coupled resonator filter device includes a bottom electrode, a piezoelectric layer disposed on the bottom electrode, and a top contour electrode disposed on the piezoelectric layer. The top contour electrode includes first and second top comb electrodes. The first top comb electrode include a first top bus bar and multiple first top fingers extending in a first direction from the first top bus bar. The second top comb electrode includes a second top bus bar and multiple second top fingers extending in a second direction from the second top bus bar, the second direction being substantially opposite to the first direction such that the first and second top fingers form a top interleaving pattern providing an acoustic filter having an apodized shape.

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.

Circuitry includes an input node, an output node, acoustic filtering circuitry, an inductive element, and a capacitor. The acoustic filtering circuitry includes an acoustic filtering input node and an acoustic filtering output node. The inductive element is coupled in series with the acoustic filtering circuitry between the input node and the output node such that the inductive element is coupled between the input node and the acoustic filtering input node and the acoustic filtering output node is coupled to the output node. The capacitor is coupled in parallel with the acoustic filtering circuitry and the inductive element between the input node and the output node. Providing the inductive element in series with the acoustic filtering circuitry and the capacitor in parallel with the acoustic filtering circuitry and the inductive element provides a highly selective notch filter response between the input node and the output node with high attenuation.