An acoustic wave filter device includes first and second acoustic wave filters provided on a piezoelectric substrate, an insulating layer that is provided on the piezoelectric substrate and has a smaller dielectric constant than the piezoelectric substrate, a first wiring conductor electrically connected to an electrode of the first acoustic wave filter, a second wiring conductor electrically connected to an electrode of the second acoustic wave filter, the first wiring conductor and the second wiring conductor facing each other on the insulating layer in plan view, and a ground conductor located between the insulating layer and the piezoelectric substrate in a region A circumscribing the first wiring conductor and the second wiring conductor on the insulating layer in plan view.

An acoustic wave device includes a piezoelectric layer and first and second electrodes facing each other in a direction intersecting a thickness direction of the piezoelectric layer. The acoustic wave device utilizes a bulk wave in a thickness-shear primary mode. A material of the piezoelectric layer is lithium niobate or lithium tantalate. At least a portion of each of the first and second electrodes is embedded in the piezoelectric layer.

An acoustic wave device includes in order a substrate, an acoustic reflection layer, a piezoelectric layer, an IDT electrode including a pair of comb electrodes, and wiring electrodes. The acoustic reflection layer includes a low Z dielectric layer, a high Z dielectric layer below the low Z dielectric layer and having an acoustic impedance higher than that of the low Z dielectric layer, and a metal layer above the low Z dielectric layer and having an acoustic impedance higher than that of the low Z dielectric layer. When the acoustic reflection layer is viewed in plan, in a region encompassing the IDT electrode and the wiring electrodes but no IDT electrodes other than the IDT electrode, an area including the metal layer is smaller than an area including the high Z dielectric layer.

An improved DMS filter with electrode structures between a first port and a second port is provided. Wiring junctions are realized in multilayer crossing with dielectric material in between. There are insulating patches (L2) between crossing conductor layers (L1,L3). Signal wirings may be realized with multiple conductor layers (L1, L3) to reduce wiring resistance and the upper conductor layer (L3) of the signal wiring may partly overlap the insulating patches (L2). The insulating patches (L2) may extend over the acoustic path to achieve temperature compensation.

Acoustic wave devices and interdigital transducer (IDT) arrangements for surface acoustic wave (SAW) devices are disclosed. Representative SAW devices are described herein that provide sharp transitions between passband frequencies and frequencies that are outside of desired passbands. A SAW device may include several IDTs arranged between reflective structures on a piezoelectric material and one or more additional IDTs or electrode pairs that are configured to modify the influence of parasitic capacitance, or other internal device capacitance, thereby improving steepness on the upper side of a passband as well as improving rejection for frequencies outside of the passband. The one or more additional IDTs or electrode pairs may be configured as at least one of a capacitor, an IDT capacitor, an IDT with a floating electrode, or combinations thereof.

Acoustic wave devices and interdigital transducer (IDT) arrangements for surface acoustic wave (SAW) devices are disclosed. Representative SAW devices are described herein that provide sharp transitions between passband frequencies and frequencies that are outside of desired passbands. A SAW device may include several IDTs arranged between reflective structures on a piezoelectric material and one or more additional IDTs or electrode pairs that are configured to modify the influence of parasitic capacitance, or other internal device capacitance, thereby improving steepness on the upper side of a passband as well as improving rejection for frequencies outside of the passband. The one or more additional IDTs or electrode pairs may be configured as at least one of a capacitor, an IDT capacitor, an IDT with a floating electrode, or combinations thereof.

A surface acoustic wave device includes a piezoelectric substrate, a supportive layer, a cover layer and a pillar bump. The supportive layer is disposed on the piezoelectric substrate and around a transducer, the cover layer covers the supportive layer, and the pillar bump is located in a lower via hole of the supportive layer and an upper via hole of the cover layer. The upper via hole has a lateral opening located on a lateral surface of the cover layer, and the pillar bump in the cover layer protrudes from the lateral surface of the cover layer via the lateral opening.

A radio-frequency module (20) includes a module substrate (50) and a filter (21). The filter (21) has a sensitive GND electrode and a non-sensitive GND electrode that are connected to an external-connection ground terminal of the module substrate (50), and parallel-arm resonators. An inductance component generated by the sensitive GND electrode shifts, by a first shift amount, an attenuation pole that corresponds to a parallel-arm resonator and that is formed near a pass band. An inductance component generated by the non-sensitive GND electrode shifts, by a second shift amount, an attenuation pole that corresponds to a parallel-arm resonator and that is formed near the pass band. The first shift amount is larger than the second shift amount, and the distance between the sensitive GND electrode and the external-connection ground terminal is smaller than the distance between the non-sensitive GND electrode and the external-connection ground terminal.

A composite filter device includes a common terminal disposed on an element substrate including a piezoelectric layer, first and second band pass filters disposed on the element substrate, and connected at one end thereof to the common terminal, a shield electrode interposed between a signal line and the first band pass filter, the signal line being disposed on the element substrate and connecting the common terminal to the first and second band pass filters, and an inductor connected between the shield electrode and a reference potential line.

An acoustic wave filter device includes a plurality of acoustic wave resonators. Each of the acoustic wave resonators includes a piezoelectric layer and an IDT electrode provided on the piezoelectric layer. On a surface opposite to a surface of the piezoelectric layer on which the IDT electrode is provided, a low-acoustic-velocity film and a substrate made of a semiconductor are stacked. A routing line electrically connected to an antenna terminal is provided on an insulating film provided on the piezoelectric layer.