A BAW resonator filter can include a BAW resonator pass-band filter ladder, the BAW resonator pass-band filter ladder can be configured to pass frequency components of an input signal in a pass-band of frequencies received at an input node of the BAW resonator pass-band filter ladder to an output node of the BAW resonator pass-band filter ladder. A first rejection-band series resonator can be coupled in series between an input port of the BAW resonator pass-band filter ladder and the input node, the first rejection-band series resonator can have a first anti-resonant frequency peak in a rejection-band of frequencies that is less than the pass-band of frequencies. A second rejection-band series resonator can be coupled in series between an output port of the BAW resonator filter and the output node, the second rejection-band series resonator can have a second anti-resonant frequency peak in the rejection-band of frequencies.

Aspects of this disclosure relate to acoustic wave filters that include a Lamb wave resonator and a second acoustic wave resonator that is a different type of acoustic wave resonator than the Lamb wave resonator. The different type of resonator can be a film bulk acoustic wave resonator for example. Some embodiments of this disclosure relate to an acoustic wave filter that includes the Lamb wave resonator and the second acoustic wave resonator. Some embodiments of this disclosure related to different respective acoustic wave filters including the Lamb wave resonator and the second acoustic wave resonator, in which the Lamb wave resonator and the second acoustic wave resonator are implemented on a common substrate.

An electrical device includes an electronic component, a membrane and a cover. The electronic component has a first surface and a second surface opposite to the first surface. The electronic component has a cavity extending from the first surface of the electronic component into the electronic component. The membrane is disposed within the cavity of the electronic component. The cover is disposed on the first surface of the electronic component.

Film bulk acoustic resonator having suppressed lateral mode. In some embodiments, a film bulk acoustic resonator can include a piezoelectric layer having a first side and a second side, a first electrode having a first lateral shape implemented on the first side of the piezoelectric layer, and a second electrode having a second lateral shape implemented on the second side of the piezoelectric layer. The first and second lateral shapes can be selected and arranged to provide a resonator shape defined by an outline of an overlap of the first and second electrodes. The resonator shape can include N curved sections joined by N vertices of an N-sided polygon. The resonator shape can be configured to have no axis of symmetry.

Aspects of this disclosure relate to acoustic wave filters that include a Lamb wave resonator and a second acoustic wave resonator that is a different type of acoustic wave resonator than the Lamb wave resonator. The different type of resonator can be a film bulk acoustic wave resonator for example. Some embodiments of this disclosure relate to an acoustic wave filter that includes the Lamb wave resonator and the second acoustic wave resonator. Some embodiments of this disclosure related to different respective acoustic wave filters including the Lamb wave resonator and the second acoustic wave resonator, in which the Lamb wave resonator and the second acoustic wave resonator are implemented on a common substrate.

A filter includes a series unit including a plurality of series resonators, and a shunt unit including a plurality of shunt resonators, wherein each of the plurality of shunt resonators is disposed between the plurality of series resonators and a ground. Each of the plurality of series resonators and the plurality of shunt resonators comprises a volume acoustic resonator, and a resonance frequency of a portion of shunt resonators among the plurality of shunt resonators may be equal to a resonance frequency of the plurality of series resonators.

Devices and systems useful in concurrently receiving and transmitting Wi-Fi signals and Bluetooth signals in the same frequency band are provided. By way of example, an electronic device includes a transceiver configured to transmit data and to receive data over channels of a first wireless network and a second wireless network concurrently. The transceiver includes a plurality of filters configured to allow the transceiver to transmit the data and to receive the data in the same frequency band by reducing interference between signals of the first wireless network and the second wireless network.

An acoustic wave device is disclosed. The acoustic wave device can include a transmit filter that includes bulk acoustic wave resonators and a series surface acoustic wave resonator that is coupled between the bulk acoustic wave resonators and a transmit output node. The acoustic wave device can also include a loop circuit that is coupled to the transmit filter. The loop circuit can generate an anti-phase signal to a target signal at a particular frequency.

Multiplexers are disclosed. A multiplexer can include a first filter and a second filter that are coupled to a common node. The second filter can include a first type of acoustic wave resonators (e.g., bulk acoustic wave resonators) and a series acoustic wave resonator of a second type (e.g., a surface acoustic wave resonator) that is coupled between the acoustic wave resonators of the first type and the common node. The first filter can provide a single-ended radio frequency signal. In certain embodiments, the first filter can be a receive filter and the second filter can be a transmit filter.

Bulk acoustic wave (BAW) resonators, and particularly shaped border (BO) rings for BAW resonators are disclosed. Top electrode arrangements are disclosed that include a BO ring arranged about a periphery of a top electrode, where the BO ring forms a top surface having a shape that is sloped or graded in comparison to planar surfaces of the top electrode. The top surface of the BO ring may be arranged such that a height of the top surface is graded in a descending manner toward a central region of the BAW resonator. BAW resonators as disclosed herein are provided with high quality factors and suppression of spurious modes while also providing reduced acoustic leakage and mode conversion.