Methods and apparatuses for measuring a phase noise level in an input signal are disclosed. An input signal can be delayed to generate a delayed version of the input signal. Next, a phase difference can be detected between the input signal and the delayed version of the input signal. A phase noise level in the input signal can then be determined based on the detected phase difference. The measured phase noise level can then be used to suppress phase noise in the input signal.

An elastic wave device includes an IDT electrode on a piezoelectric substrate, in which the IDT electrode includes first electrode fingers and second electrode fingers, where a portion in which the first electrode fingers and the second electrode fingers overlap with each other in an elastic wave propagation direction is defined as an intersection region including in a direction in which the first and second electrode fingers extend, a center region located on a center side and first and second edge regions respectively located on both sides of the center region, in the first and second edge regions, grooves defining recess portions are provided on the piezoelectric substrate, the first and second electrode fingers are provided inside of the grooves as the recess portions and are disposed on the piezoelectric substrate in the grooves.

The invention relates to an acousto-optic deflector comprising a bulk of acousto-optic medium and acoustic wave generator coupled to the bulk, characterized by that the acoustic wave generator comprises at least two different electro-acoustic transducers for generating acoustic waves in the bulk.

In an elastic wave device, an interdigital transducer (IDT) electrode is disposed on a piezoelectric substrate. In at least one of first and second electrode fingers of the IDT electrode, elongated sections with a widthwise dimension larger than that of a center of the first and second electrode fingers in a longitudinal direction are provided in at least one of a portion closer to a base end of the first or second electrode finger and a portion closer to a leading end of the first or second electrode finger than a central region of the first or second electrode finger. At least one of first and second busbars includes a plurality of openings provided separately from each other along the longitudinal direction of the first and second busbars.

An elastic wave device includes an IDT provided on a piezoelectric substrate. The IDT includes edge areas in which an elastic wave propagation velocity is slower than an elastic wave propagation velocity in a center area of an electrode finger intersecting region. The edge areas are provided on both sides of the center area in an intersecting width direction. The IDT includes a first section where the propagation velocity in the center area is relatively fast and a second section where the propagation velocity in the center area is relatively slow in the elastic wave propagation direction. In accordance with the propagation velocities in the center areas of the first and second sections, the widths and propagation velocities in the edge areas of the first and second sections excite a piston mode.

An electronic component includes: a first substrate; a second substrate that includes a functional element formed on a lower surface of the second substrate, the second substrate being mounted on the first substrate so that the functional element faces an upper surface of the first substrate across an air gap; and an insulating film that is located on the upper surface of the first substrate, overlaps with at least a part of the functional element in plan view, faces the functional element across the air gap, and has a film thickness that is more than half of a distance between a lower surface of the functional element and the upper surface of the first substrate.

A multiplexer includes elastic wave filters with different pass bands, a common terminal to which an inductance element is serially connected in a connection path between an antenna element and the common terminal; and an inductance element. Among the elastic wave filters, a reception input terminal of a first reception filter is connected to the common terminal via the inductance element and is connected to a parallel resonator. Transmission output terminals of transmission filters and a reception input terminal of a second reception filter are connected to the common terminal, are connected to series resonators, and are not connected to parallel resonators.

A surface acoustic wave device includes a piezoelectric substrate, an IDT electrode, a support layer, a cover layer, and a pillar-shaped electrode. The IDT electrode is provided on a main surface of the piezoelectric substrate. The support layer is disposed around a region where the IDT electrode is provided and has a larger height from the main surfaces than a height of the IDT electrode therefrom. The cover layer is disposed on the support layer and covers the IDT electrode. The pillar-shaped electrode is located on one of the main surfaces where the pillar-shaped electrode is in contact with the support layer. The pillar-shaped electrode is electrically connected to the IDT electrode. The pillar-shaped electrode includes a top surface and a side surface. Each of the top surface and the side surface includes a portion exposed to outside.

A radio frequency module includes an elastic wave filter and a low-noise amplifier that amplifies an RF signal output from the elastic wave filter. An output impedance of the elastic wave filter is positioned, on a Smith chart, closer to a noise matching impedance than to a gain matching impedance, at a frequency of at least one of a low frequency end and a high frequency end of a passband of the elastic wave filter. The noise matching impedance indicates the output impedance where a noise figure of the LNA becomes minimum. The gain matching impedance indicates the output impedance where a gain of the LNA becomes maximum.

Acoustic filtering circuitry includes a piezoelectric layer, a dielectric layer, a plurality of acoustic resonators, and a capacitor. The dielectric layer is over a surface of the piezoelectric layer. The plurality of acoustic resonators each includes a transducer on the surface of the piezoelectric layer such that the transducer is between the piezoelectric layer and the dielectric layer. The capacitor includes a first plate on the surface of the piezoelectric layer such that the first plate is between the piezoelectric layer and the dielectric layer and a second plate over the first plate such that the second plate and the first plate are separated by at least a portion of the dielectric layer.