A filter includes a series arm resonator, a first parallel arm resonance circuit and a second parallel arm resonance circuit. The each of the first parallel arm resonance circuit and the second parallel arm resonance circuit includes: a parallel arm resonator that is connected to a node; a pair of elements consisting of a capacitor and a switch, which are connected in parallel with each other, that is connected in series with the parallel arm resonator; and an inductor that is provided on a path that connects the node and ground to each other via the switch. The inductance value of the inductor of the first parallel arm resonance circuit and the inductance value of the inductor of the second parallel arm resonance circuit are substantially equal to each other.

Embodiments may relate to a radio frequency (RF) front-end module (FEM). The RF FEM may include an integrated die with an active portion and an acoustic wave resonator (AWR) portion adjacent to the active portion. The RF FEM may further include a lid coupled with the die. The lid may at least partially overlap the AWR portion at a surface of the die. Other embodiments may be described or claimed.

A duplexer is disclosed. In an embodiment, the duplexer includes a Tx filter and an Rx filter, wherein the Tx filter includes first series-interconnected basic elements, each first basic element having a first electroacoustic resonator and first impedance converters interconnected in series between the first basic elements, wherein the Rx filter comprises second series-interconnected basic elements, each second basic element having a second electroacoustic resonator and second impedance converters interconnected in series between the second basic elements, wherein the first impedance converters in the Tx filter are impedance inverters, wherein the first resonators of the first basic elements in the Tx filter are only series resonators, wherein the second impedance converters in the Rx filter are admittance inverters, and wherein the second resonators of the second basic elements in the Rx filter are only parallel resonators.

A front end module (FEM) for a 5.6 GHz Wi-Fi acoustic wave resonator RF filter circuit. The device can include a power amplifier (PA), a 5.6 GHz resonator, and a diversity switch. The device can further include a low noise amplifier (LNA). The PA is electrically coupled to an input node and can be configured to a DC power detector or an RF power detector. The resonator can be configured between the PA and the diversity switch, or between the diversity switch and an antenna. The LNA may be configured to the diversity switch or be electrically isolated from the switch. Another 5.6 GHZ resonator may be configured between the diversity switch and the LNA. In a specific example, this device integrates a 5.6 GHz PA, a 5.6 GHZ bulk acoustic wave (BAW) RF filter, a single pole two throw (SP2T) switch, and a bypassable LNA into a single device.

Techniques are disclosed for monolithic co-integration of thin-film bulk acoustic resonator (TFBAR, also called FBAR) devices and III-N semiconductor transistor devices. In accordance with some embodiments, one or more TFBAR devices including a polycrystalline layer of a piezoelectric III-N semiconductor material may be formed alongside one or more III-N semiconductor transistor devices including a monocrystalline layer of III-N semiconductor material, over a commonly shared semiconductor substrate. In some embodiments, either (or both) the monocrystalline and the polycrystalline layers may include gallium nitride (GaN), for example. In accordance with some embodiments, the monocrystalline and polycrystalline layers may be formed simultaneously over the shared substrate, for instance, via an epitaxial or other suitable process. This simultaneous formation may simplify the overall fabrication process, realizing cost and time savings, at least in some instances.

A radio frequency filter includes at least a first sub-filter and a second sub-filter connected in parallel between a first port and a second port. Each of the sub-filters has a piezoelectric plate having front and back surfaces, the back surface attached to a substrate, and portions of the piezoelectric plate forming diaphragms spanning respective cavities in the substrate. A conductor pattern is formed on the front surface of the plate, the conductor pattern includes interdigital transducers (IDTs) of a respective plurality of resonators, with interleaved fingers of each IDT disposed on a respective diaphragm of the plurality of diaphragms. A thickness of the portions of the piezoelectric plate of the first sub-filter is different from a thickness of the portions of the piezoelectric plate of the second sub-filter.

Embodiments of the invention include a piezoelectric package integrated filtering device that includes a film stack. In one example, the film stack includes a first electrode, a piezoelectric material in contact with the first electrode, and a second electrode in contact with the piezoelectric material. The film stack is suspended with respect to a cavity of an organic substrate having organic material and the film stack generates an acoustic wave to be propagated across the film stack in response to an application of an electrical signal between the first and second electrodes.

A reception filter includes a parallel arm resonator, a first longitudinally coupled resonance device including first acoustic wave resonators, and a second longitudinally coupled resonance device including second acoustic wave resonators, and cascade-connected to the first longitudinally coupled resonance device. Each of the first and second acoustic wave resonators include one end connected to a ground, the parallel arm resonator and the first and second longitudinally coupled resonance devices are provided on a piezoelectric substrate, and a ground to which the parallel arm resonator is connected, a ground to which at least one of the first acoustic wave resonators is connected, and a ground to which at least one of the second acoustic wave resonators is connected are commonly connected on the piezoelectric substrate.

A method of fabricating the semiconductor device includes the following steps. Forming a sacrificial portion at a first end of an upper electrode layer before a passivation layer is formed so that it supports a corresponding end portion of the passivation layer, making the passivation layer not suspended at all. In this way, the suspended portion of the passivation layer will not be damaged during the formation of a contact pad. In addition, subsequent to the formation of the contact pad, removing the sacrificial portion, freeing up a space under the end portion of the passivation layer so that the end portion itself becomes a suspended portion. This can ensure performance of the resulting semiconductor device.

A bulk acoustic resonator includes: a substrate including an upper surface on which a substrate protection layer is disposed; and a membrane layer forming a cavity together with the substrate, wherein a thickness deviation of either one or both of the substrate protection layer and the membrane layer is 170 or less.