摘要:
A piezoelectric thin-film resonator includes: a lower electrode provided on a substrate; a piezoelectric film provided on the lower electrode; an upper electrode provided on the piezoelectric film so as to face the lower electrode across the piezoelectric film to thus define a resonance portion; and a weight load film provided on the upper electrode, the weight load film being provided in the resonance portion and having an area smaller than that of the resonance portion.
摘要:
An acoustic wave device includes a main resonator and a sub resonator each having a substrate, a lower electrode provided on the substrate, a piezoelectric film provided on the lower electrode, and an upper electrode provided on an upper side of the piezoelectric film. A frequency control film is provided on an upper side of a resonance area in which the upper electrode and the lower electrode face each other in at least one of the main resonator and the sub resonator. The frequency control film has multiple convex patterns, and the convex patterns are arranged with a common pitch for spurious adjustment and with different areas in the main resonator and the sub resonator.
摘要:
An acoustic wave device includes a main resonator and a sub resonator each having a substrate, a lower electrode provided on the substrate, a piezoelectric film provided on the lower electrode, and an upper electrode provided on an upper side of the piezoelectric film. The sub resonator has a mass addition film on the upper electrode in a resonance area in which the upper electrode and the lower electrode face each other. At least one of the main resonator and the sub resonator is provided with a frequency control film on an upper side of the resonance area, and the frequency control film has a weight per unit area smaller than a weight of the mass addition film per unit area.
摘要:
A piezoelectric thin-film resonator includes: a lower electrode provided on a substrate; a piezoelectric film that is provided on the lower electrode and includes at least two layers; an upper electrode that is provided on the piezoelectric film and has a region sandwiching the piezoelectric film with the lower electrode and facing the lower electrode; and an insulating film that is provided in a region in which the lower electrode and the upper electrode face each other and between each of the at least two layers, wherein an upper face of the insulating film is flatter than a lower face of the insulating film.
摘要:
A duplexer includes a transmission filter and a reception filter having different passbands, wherein: first resonators that are series resonators or parallel resonators included in the transmission and reception filters so as to form a skirt characteristic at a guard band side are a temperature compensated type piezoelectric thin film resonator or a surface acoustic wave resonator using Love waves, and second resonators that form a skirt characteristic at an opposite side to the guard band are one of a temperature non-compensated type piezoelectric thin film resonator, a surface acoustic wave resonator using a lithium tantalate substrate or a substrate made by bonding a lithium tantalate substrate on a sapphire substrate, and a surface acoustic wave resonator using Love waves.
摘要:
A resonant device includes first and second piezoelectric thin film resonators. The first piezoelectric thin film resonator includes a substrate, a first lower electrode formed on the substrate, a first piezoelectric film formed over the first lower electrode, and a first upper electrode formed on the piezoelectric film and opposed to the first lower electrode. The second piezoelectric thin film resonator includes a second lower electrode formed above the first upper electrode, a second piezoelectric film formed over the second lower electrode, and a second upper electrode formed on the piezoelectric film and opposed to the second lower electrode. The first membrane region in which the first lower electrode opposes to the first upper electrode through the first piezoelectric film and a second membrane region in which the second lower electrode opposes to the second upper electrode through the second piezoelectric film are laminated through a second cavity.
摘要:
A resonant device includes first and second piezoelectric thin film resonators. The first piezoelectric thin film resonator includes a substrate, a first lower electrode formed on the substrate, a first piezoelectric film formed over the first lower electrode, and a first upper electrode formed on the piezoelectric film and opposed to the first lower electrode. The second piezoelectric thin film resonator includes a second lower electrode formed above the first upper electrode, a second piezoelectric film formed over the second lower electrode, and a second upper electrode formed on the piezoelectric film and opposed to the second lower electrode. The first membrane region in which the first lower electrode opposes to the first upper electrode through the first piezoelectric film and a second membrane region in which the second lower electrode opposes to the second upper electrode through the second piezoelectric film are laminated through a second cavity.
摘要:
The invention provides an optical modulator which suppresses the loss of a microwave which advances through an electrode and of light which propagates in a waveguide and makes the losses in individual arm waveguides substantially equal to each other to suppress the deterioration of the extinction coefficient to improve the transmission quality. The optical modulator includes a substrate having an electro-optical effect and having a ridge, first and second grooves and first and second banks formed thereon, a Mach-Zehnder optical waveguide, an electrode, and first and second recesses formed at symmetrical positions with respect to the ridge on the first and second banks, respectively. The optical modulator is applied, for example, to a transmission side apparatus for a long distance optical transmission system.
摘要:
The invention provides an optical device which can lower the drive voltage which is used as one of the parameters for performance evaluation of the optical device. The optical device includes a substrate having first and second ridges, first and second grooves, a third groove, and first and second banks formed thereon, a Mach-Zehnder optical waveguide formed on the substrate, and an electrode set including first and second signal electrodes and a grounding electrode for controlling light which propagates in the optical waveguide. The grounding electrode extends to the first groove adjacent to the first bank and the second groove adjacent to the second bank. The optical device is applied, for example, to a transmission side apparatus for a long distance optical transmission system.
摘要:
An acousto-optical device includes a light waveguide path formed on an acousto-optical substrate, a transducer which crosses the light waveguide path and propagates a surface acoustic wave along the light waveguide path, and a buffer layer provided so that finger electrodes of the transducer are spaced apart from the light waveguide path in crossing portions in which the finger electrodes cross the light waveguide path. The finger electrodes have other portions which directly contact the substrate.