Abstract: A method for fabricating a surface acoustic wave (SAW) device includes forming an interdigital transducer (IDT) having lead-out portions and arrays of interdigital electrodes on a substrate, wherein the interdigital electrodes include central portions, end portions, and intermediate portions between the end portions and the lead-out portions; forming a protective layer on the IDT; forming a first temperature compensation layer on the protective layer; forming openings in the first temperature compensation layer to expose portions of the protective layer on the central portions and the intermediate portions of the interdigital electrodes; and etching the exposed portions of the protective layer, and etching the central portions and the intermediate portions of the interdigital electrodes to a preset thickness, to form protruding structures at the end portions of the interdigital electrodes.

Abstract: Methods of making packaged surface acoustic wave devices are provided. The method may include forming a photosensitive resin coat over a cavity-defining structure encapsulating a surface acoustic wave device. The photosensitive resin coat may be formed using a spin-coating process, and then patterned to form a desired shape. Portions of the photosensitive resin may be removed from areas near the edge of the die, to facilitate separation of a wafer into individual dies. The method may also include forming a conductive structure using a plating process, where the conductive structure is located between the resin coat and the cavity defining structure. The photosensitive resin can include a phenol resin. The packaged surface acoustic wave devices made using a photosensitive resin coat may be relatively thin, and may have a height of less than 220 micrometers.

Abstract: Embodiments of this disclosure relate to reducing coupling between acoustic wave resonators. An isolation region of a substrate can be located between acoustic wave resonators. The isolation region can reduce capacitive coupling through the substrate between the acoustic wave resonators. In certain embodiments, the isolation region can be located between acoustic wave resonators of different filters to thereby increase isolation between the filters.

Abstract: A tunable filter with wide tuning range and high out-of-band rejection is achieved with a tunable bandpass filter and a number of cascaded, fixed frequency Lame-Mode Resonators (LMRs) notch filters or other resonators. In some embodiments, the filter can be implemented with all of the elements on an integrated circuit, saving space for use in applications such as mobile phones or other mobile communication devices.

Abstract: Acoustic resonators and filter devices, and methods for making acoustic resonators and filter devices. An acoustic resonator includes a substrate having a surface and a single-crystal piezoelectric plate having front and back surfaces. The back surface is attached to the surface of the substrate except for a portion of the piezoelectric plate forming a diaphragm spanning a cavity in the substrate. A conductor pattern formed is formed on the front surface of the piezoelectric plate, including an interdigital transducer (IDT) with interleaved fingers of the IDT on the diaphragm. An insulating layer is formed between the piezoelectric plate and portions of the conductor pattern other than the interleaved fingers.

Abstract: Band N77 bandpass filters include a first plurality of transversely-excited film bulk acoustic resonators (XBARs) on a first chip comprising a first rotated YX-cut lithium niobate piezoelectric plate having a thickness less than or equal to 535 nm, and a second plurality of XBARs on a second chip comprising a second rotated YX-cut lithium niobate piezoelectric plate having a thickness greater than or equal to 556 nm. A circuit card is coupled to the first chip and the second chip. The circuit card includes conductors for making electrical connections between the first chip and the second chip.

Abstract: An acoustic wave device includes a support substrate, a piezoelectric layer provided over the support substrate, comb-shaped electrodes disposed on the piezoelectric layer, each of the comb-shaped electrodes including electrode fingers exciting an acoustic wave, a temperature compensation film interposed between the support substrate and the piezoelectric layer and having a temperature coefficient of an elastic constant opposite in sign to that of the piezoelectric layer, a boundary layer interposed between the support substrate and the temperature compensation film, an acoustic velocity of a bulk wave propagating through the boundary layer being higher than an acoustic velocity of a bulk wave propagating through the temperature compensation film and being lower than an acoustic velocity of a bulk wave propagating through the support substrate, and an intermediate layer interposed between the support substrate and the boundary layer and having a Q factor less than a Q factor of the boundary layer.

Abstract: Surface acoustic wave devices and related methods. In some embodiments, a surface acoustic wave device for providing resonance of a surface acoustic wave having a wavelength ? can include a quartz substrate and a piezoelectric plate formed from LiTaO3 or LiNbO3 disposed over the quartz substrate. The piezoelectric plate can have a thickness greater than 2?. The surface acoustic wave device can further include an interdigital transducer electrode formed over the piezoelectric plate. The interdigital transducer electrode can have a mass density ? in a range 1.50 g/cm3<??6.00 g/cm3, 6.00 g/cm3<??12.0 g/cm3, or 12.0 g/cm3<??23.0 g/cm3, and a thickness greater than 0.148?, greater than 0.079?, or greater than 0.036?, respectively.

Abstract: Devices and methods related to film bulk acoustic resonators. In some embodiments, a film bulk acoustic resonator can be manufactured by a method that includes forming a first electrode having a first lateral shape and providing a piezoelectric layer on the first electrode. The method can further include forming a second electrode having a second lateral shape on the piezoelectric layer such that the piezoelectric layer is between the first and second electrodes. The forming of the first electrode and the forming of the second electrode can include selecting and arranging the first and second lateral shapes to provide a resonator shape defined by an outline of an overlap of the first and second electrodes, such that the resonator shape includes N curved sections joined by N vertices of an N-sided polygon, and such that the resonator shape has no axis of symmetry.

Abstract: Acoustic resonators are disclosed. An acoustic resonator includes a substrate having a surface and a single-crystal piezoelectric plate having front and back surfaces. The back surface is attached to the surface of the substrate except for a portion of the piezoelectric plate forming a diaphragm spanning a cavity in the substrate. An interdigital transducer (IDT) is formed on the front surface of the piezoelectric plate. The IDT includes: a first busbar and a second busbar disposed on respective portions of the piezoelectric plate other than the diaphragm; a first set of elongate fingers extending from the first bus bar onto the diaphragm; and a second set of elongate fingers extending from the second bus bar onto the diaphragm, the second set of elongate fingers interleaved with the first set of elongate fingers.

Abstract: An RF diplexer circuit device using modified lattice, lattice, and ladder circuit topologies. The diplexer can include a pair of filter circuits, each with a plurality of series resonator devices and shunt resonator devices. In the ladder topology, the series resonator devices are connected in series while shunt resonator devices are coupled in parallel to the nodes between the resonator devices. In the lattice topology, a top and a bottom serial configurations each includes a plurality of series resonator devices, and a pair of shunt resonators is cross-coupled between each pair of a top serial configuration resonator and a bottom serial configuration resonator. The modified lattice topology adds baluns or inductor devices between top and bottom nodes of the top and bottom serial configurations of the lattice configuration. A multiplexing device or inductor device can be configured to select between the signals coming through the first and second filter circuits.

Abstract: An acoustic wave filter device is disclosed. The device includes an acoustic wave filter element, and a first resonator and a second resonator coupled to the acoustic wave filter element. The acoustic wave filter element includes interdigited input electrodes and output electrodes located on a top surface of a piezoelectric layer. Each of the first and the second resonators includes a top electrode on the top surface, and a bottom electrode on the bottom surface of the piezoelectric layer. At least one of each of the first and the second resonators' electrodes is electrically connected to the acoustic wave filter element. The first resonator has a first notch in resonator impedance at a first frequency. The second resonator includes a first mass loading layer on the second resonator electrode such that the second resonator has a second notch in resonator impedance at a second frequency different from the first frequency.

Abstract: The present invention includes a method of creating electrical air gap low loss low cost RF mechanically and thermally stabilized interdigitated resonate filter in photo definable glass ceramic substrate. Where a ground plane may be used to adjacent to or below the RF filter in order to prevent parasitic electronic signals, RF signals, differential voltage build up and floating grounds from disrupting and degrading the performance of isolated electronic devices by the fabrication of electrical isolation and ground plane structures on a photo-definable glass substrate.

Abstract: A bonded body includes a supporting substrate; a piezoelectric material substrate; a first bonding layer provided on the supporting substrate and having a composition of Si(1-x)Ox (0.008?x?0.408); a second bonding layer provided on the piezoelectric material substrate and having a composition of Si(1-y)Oy (0.008?y?0.408); and an amorphous layer provided between the first bonding layer and second bonding layer. The oxygen ratio of the amorphous layer is higher than the oxygen ratio of the first bonding layer and oxygen ratio of the second bonding layer.

Abstract: Acoustic resonators and filter devices. An acoustic resonator includes a substrate having a surface and a single-crystal piezoelectric plate having front and back surfaces. The back surface is attached to the surface of the substrate except for a portion of the piezoelectric plate forming a diaphragm spanning a cavity in the substrate. A conductor pattern formed is formed on the front surface of the piezoelectric plate, including an interdigital transducer (IDT) with interleaved fingers of the IDT on the diaphragm. The substrate and the piezoelectric plate are the same material.

Abstract: In a filter device, a transversal elastic wave filter, which defines a delay element, is connected in parallel with a band pass filter. The transversal elastic wave filter has the same amplitude characteristic as and the opposite phase to the band pass filter at a desired frequency inside an attenuation range of the band pass filter. When a wavelength determined by an electrode finger period of IDTs and is denoted by ?, the distance between the first IDT and the second IDT of the elastic wave filter is about 12? or less.

Abstract: An acoustic resonator device with low thermal impedance has a substrate and a single-crystal piezoelectric plate having a back surface attached to a top surface of the substrate via a bonding oxide (BOX) layer. An interdigital transducer (IDT) formed on the front surface of the plate has interleaved fingers disposed on the diaphragm. The piezoelectric plate and the BOX layer are removed from a least a portion of the surface area of the device to provide lower thermal resistance between the IDT and the substrate.

Abstract: A surface acoustic wave device includes a piezoelectric substrate, an interdigital transducer (IDT) electrode on the substrate, a cover over the substrate and IDT electrode, and hollow spaces between the IDT electrode and the cover. The hollow spaces are defined by partition supports between the substrate and the cover. The partition supports include a first and second partition supports extending in a first direction without contacting each other. The first and second partition supports each include first and second ends along the first direction. The first and second direction perpendicular to the first direction. The first end of the first partition support is closer to an outer periphery of the substrate than is the second end, and the first end of the second partition support is farther away from the outer periphery than is the second end.

Abstract: A branch-line coupler, adapted to radio frequency circuits, includes an input port, a first output port, a second output port, an isolated port, a first transmission line, a second transmission line, a first bent branch line, and a second bent branch line. The first transmission line is electrically connected between the input port and the first output port, and carries two open branches. The second transmission line is electrically connected between the isolated port and the second output port, and carries two open branches. The first bent branch line is electrically connected between the input port and the isolated port. The second bent branch line is electrically connected between the first output port and the second output port. The open branches of the first transmission line and the second transmission line resemble the bone structure of a fish skeleton.

Abstract: Acoustic wave filter devices are disclosed. A device includes a layer providing or on a topmost layer of an acoustic reflector. The intermediary layer has a first region and a second region. The first region has a first layer thickness and the second region has a second layer thickness different from the first layer thickness. The device includes a first multilayer stack on the first region and a second multilayer stack on the second region of the intermediary layer. Each of the first and the second stacks includes a piezoelectric layer on a counter electrode that is located on the respective region, an input and an output electrode. Application of a radio frequency voltage between the input electrode and the counter electrode layer of the first stack creates acoustic resonance modes in the piezoelectric layer between the input and output electrodes of the first and the second stack.