A filter device according to an embodiment of the present disclosure includes a first filter and a second filter that are connected in parallel between a first terminal and a second terminal. The first filter includes multiple series arm resonators. The series arm resonators are disposed in series in a path from the first terminal via the first filter to the second terminal. The series arm resonators include a first series arm resonator and a second series arm resonator. Under a condition that a value obtained by dividing a difference between an antiresonance frequency and a resonance frequency of each series arm resonator by the resonance frequency is defined as a fractional bandwidth, a first fractional bandwidth of the first series arm resonator is different from a second fractional bandwidth of the second series arm resonator.

A method of plugging a hydrocarbon well includes deploying a downhole tool to remove at least a portion of a casing at a section of well to be plugged. Deploying a blocking device downhole to block a bottom of the section of well to be plugged. Deploying a plugging material downhole onto the blocking device to fill an area to be plugged. Deploying an exothermic fluid downhole, wherein activation of the exothermic material liquefies the plugging material. Allowing the plugging material and the exothermic fluid to solidify form a cast-in-place plug that fills the section of well to be plugged.

In accordance with an embodiment, a method of operating an RF system includes filtering a wideband RF signal using an adjustable center frequency bandpass filter to produce a filtered RF signal; amplifying the filtered RF signal to produce an amplified RF signal; and band stop filtering the amplified RF signal to produce a band stopped RF signal.

A front end module includes: a first filter configured to operate as a bandpass filter, and to support communications in a 4.4 GHz to 5.0 GHz band; and a second filter configured to operate as a high-pass filter, and to support communications in a 5.15 GHz to 5.835 GHz band.

An elastic wave device includes a first piezoelectric substrate made of LiNbO.sub.3, a first band-pass filter provided on the first piezoelectric substrate and including first IDT electrodes, a dielectric layer provided on the first piezoelectric substrate and covering the plurality of first IDT electrodes, a second piezoelectric substrate, a second band-pass filter provided on the second piezoelectric substrate, including second IDT electrodes, and differing from the first band-pass filter in pass band, and a band elimination filter connected to the first band-pass filter. The band elimination filter is provided on a piezoelectric substrate other than the first piezoelectric substrate.

An elastic wave device includes a first piezoelectric substrate made of LiNbO.sub.3, a first band-pass filter provided on the first piezoelectric substrate and including first IDT electrodes, a dielectric layer provided on the first piezoelectric substrate and covering the plurality of first IDT electrodes, a second piezoelectric substrate, a second band-pass filter provided on the second piezoelectric substrate, including second IDT electrodes, and differing from the first band-pass filter in pass band, and a band elimination filter connected to the first band-pass filter. The band elimination filter is provided on a piezoelectric substrate other than the first piezoelectric substrate.

Acoustic resonator devices and filters are disclosed. A piezoelectric plate is attached to a substrate, a portion of the piezoelectric plate forming a diaphragm spanning a cavity in the substrate. A first conductor pattern is formed on a surface of the piezoelectric plate. The first conductor pattern includes interleaved fingers of an interdigital transducer disposed on the diaphragm, and a first plurality of contact pads. A second conductor pattern is formed on a surface of a base, the second conductor pattern including a second plurality of contact pads. Each pad of the first plurality of contact pads is directly bonded to a respective pad of the second plurality of contact pads. A ring-shaped seal is form between a perimeter of the piezoelectric plate and a perimeter of the base.

Acoustic resonator devices and filters are disclosed. A piezoelectric plate is attached to a substrate, a portion of the piezoelectric plate forming a diaphragm spanning a cavity in the substrate. A first conductor pattern is formed on a surface of the piezoelectric plate. The first conductor pattern includes interleaved fingers of an interdigital transducer disposed on the diaphragm, and a first plurality of contact pads. A second conductor pattern is formed on a surface of a base, the second conductor pattern including a second plurality of contact pads. Each pad of the first plurality of contact pads is directly bonded to a respective pad of the second plurality of contact pads. A ring-shaped seal is form between a perimeter of the piezoelectric plate and a perimeter of the base.

A method of fabricating packaged electronic components with improved yield and at lower unit cost; the method comprising the steps of obtaining an active membrane layer on a carrier substrate, depositing a front electrode onto a front of the active membrane layer, obtaining an inner front section including at least a silicon handle or wafer, attaching an inner front end section to an outer surface of the front electrode, detaching the carrier substrate from a back surface of an active membrane on the opposite surface from the front surface on which the front electrode is deposited, patterning the active membrane layer into an array of at least one island of membrane, selectively removing the front electrode and bonding layer, selectively applying an inner passivation layer, and selectively depositing a back electrode layer on the thus exposed back surface of the active membrane.

A method of fabricating an FBAR filter device including an array of resonators, each resonator comprising a single crystal piezoelectric film sandwiched between a first metal electrode and a second metal electrode, wherein the first electrode is supported by a support membrane over an air cavity, the air cavity embedded in a silicon dioxide layer over a silicon handle, with through-silicon via holes through the silicon handle and into the air cavity, the side walls of said air cavity in the silicon dioxide layer being defined by perimeter trenches that are resistant to a silicon oxide etchant.