An acoustic wave filter device includes at least one series arm resonator and a parallel arm resonator. The series arm resonators and the parallel arm resonator are defined by acoustic wave resonators, an interdigital transducer electrode of the series arm resonators is an apodized interdigital transducer electrode subjected to apodization weighting, in the interdigital transducer electrode of the parallel arm resonator, an intersecting portion includes a central region and low acoustic velocity regions provided at both outer side portions of the central portion, an acoustic velocity of an acoustic wave in the low acoustic velocity region is lower than an acoustic velocity of an acoustic wave in the central region, and a high acoustic velocity region where an acoustic velocity of an acoustic wave is higher than that of the low acoustic velocity region is provided at an outer side portion of each of the low acoustic velocity regions.

In an acoustic wave device, an antenna end resonator that is electrically closest to a first terminal is a first acoustic wave resonator. In each of the first acoustic wave resonator and a second acoustic wave resonator, a thickness of a piezoelectric layer is about 3.5λ or less when a wavelength of an acoustic wave is denoted as λ. The first acoustic wave resonator and the second acoustic wave resonator satisfy at least one of a first condition, a second condition, and a third condition. The first condition is a condition that the first acoustic wave resonator further includes a dielectric film provided between the piezoelectric layer and an interdigital transducer electrode, and the second acoustic wave resonator does not include the dielectric film.

An elastic wave device includes a wiring board, a device chip having a resonator, and a wiring pattern electrically connected to the resonator, the device chip is electrically connected to the wiring board, and a sealing portion that seals the device chip. The wiring pattern includes a first wiring layer and a second wiring layer. The second wiring layer includes a lower metal layer in contact with an upper surface of the first wiring layer, a partition layer which is a metal layer in contact with an upper surface of the lower metal layer, and an upper metal layer in contact with an upper surface of the partition layer. The partition layer is a metal having a lower electrical conductivity than the lower metal layer and the upper metal layer.

An acoustic wave resonator includes two comb-shaped electrodes provided on a piezoelectric substrate, each of the comb-shaped electrodes including electrode fingers and a bus bar coupled to the electrode fingers, an acoustic velocity of an acoustic wave propagating through a gap region, which is located between tips of electrode fingers of one of the comb-shaped electrodes and a bus bar of the other of the comb-shaped electrodes, being equal to or greater than 0.98 times and equal to or less than 1.02 times an acoustic velocity of an acoustic wave propagating through an edge region located in an edge in an extension direction of the electrode fingers in an overlap region, and an additional film that is provided over the piezoelectric substrate from the edge region to the gap region and is not provided in a center region located further in than the edge region in the overlap region.

A front-end module may include an acoustic wave filter with a first and second interdigital transducer electrode. The first interdigital transducer electrode may be single-ended with a first input bus bar that receives an input signal and a second input bus bar connected to ground. The second interdigital transducer electrode may be differential with a first output bus bar connected to a first output terminal and a second output bus bar connected to a second output terminal. The front-end module may include a low noise amplifier (LNA) that outputs a differential signal via a differential output and has a differential input connected to the acoustic wave filter. The LNA may include a first input transistor that receives a first signal from the first output terminal of the acoustic wave filter and a second input transistor that receives a second signal from the second output terminal of the acoustic wave filter.

Aspects of this disclosure relate to a surface acoustic wave device. The surface acoustic wave device includes a piezoelectric layer and an interdigital transducer. The interdigital transducer electrode includes a pair of electrodes, each electrode having a bus bar and fingers extending from the bus bar. The interdigital transducer electrode has an interdigital region defined by a portion of the fingers of the electrodes that interdigitate with each other. A dielectric layer is disposed over the interdigital transducer electrode outside the interdigital region and configured to reduce a loss of the surface acoustic wave device.

An acoustic wave device is disclosed. The acoustic wave device can include a piezoelectric layer, an interdigital transducer electrode over the piezoelectric layer, a temperature compensation layer over the interdigital transducer electrode, and a dielectric layer that is positioned partially between the piezoelectric layer and the interdigital transducer electrode. The dielectric layer that is positioned so as to partially electro-mechanically de-couple the piezoelectric layer from the interdigital transducer electrode.

A radio-frequency filter includes a series-arm circuit on a circuit path that connects a first input/output terminal and a second input/output terminal. A parallel-arm circuit is connected to a node on the path and ground. The series-arm circuit includes a first impedance element, a first switch element connected to the first impedance element, and a series-arm resonator connected in parallel to the first impedance element and the first switch element. The parallel-arm circuit includes a first parallel-arm resonator, and a first switch circuit connected in series to the first parallel-arm resonator, the first switch circuit includes a second switch element. The first and second switch elements and the second switch elements include one or more transistors, and a gate width of the transistors included in the second switch element is larger than that of at least one of the transistors included in the first switch element.

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.

A filter device includes a filter circuit including first and second terminals and series arm resonators along a series arm connecting the first terminal and the second terminal, and an additional circuit connected in parallel at least some of the series arm resonators. The additional circuit includes first, second, and third interdigital transducer electrodes. The first interdigital transducer electrode is connected to a first node at one end portion of a series arm resonator having a lowest anti-resonant frequency of the series arm resonators, the second interdigital transducer electrode is connected to a second node having a potential different from a potential of the first node, the third interdigital transducer electrode is connected to a third node having a potential different from the potentials of the first and second nodes, and the first and second nodes are closer to the first terminal than the third node.