Abstract: A method of manufacturing a ladder filter including first and second resonators includes: forming a piezoelectric film on an entire surface of a substrate that has respective lower electrodes of the first and second resonator formed thereon, an conductive film on the piezoelectric film, and a second film on the conductive film; forming a pattern of the second film in a prescribed region in the second area; forming a first film on an entire surface of the substrate; etching the first film, forming a pattern of the first film, the second film and the conductive film in the second area, and forming a pattern of the first film and the conductive film in the first area, to form respective upper electrodes from the conductor film; and thereafter, etching the piezoelectric film to form respective patterns of the piezoelectric film in the first and second areas, respectively.

Abstract: An acoustic wave device includes piezoelectric thin-film resonators, each of which includes: a substrate; a piezoelectric thin-film on the substrate; an lower electrode provided on a first surface of the piezoelectric film; an upper electrode provided on a second surface of the piezoelectric film opposite to the first surface; and a first addition film that is provided in a resonance portion in which the lower electrode and the upper electrode face each other through the piezoelectric film and is located between the piezoelectric thin-film and the upper electrode, the first addition film having a shape different from that of the resonance portion.

Abstract: An acoustic wave device includes: a substrate; a piezoelectric film located on the substrate; a lower electrode and an upper electrode facing each other across the piezoelectric film, at least one of the lower electrode and the upper electrode including a first conductive film and a second conductive film formed on the first conductive film; an insulating film sandwiched between the first conductive film and the second conductive film and having a temperature coefficient of an elastic constant opposite in sign to a temperature coefficient of an elastic constant of the piezoelectric film; and a third conductive film formed on edge surfaces of the insulating film and the second conductive film and causing electrical short circuits between the first conductive film and the second conductive film.

Abstract: An acoustic wave device includes a substrate and a plurality of piezoelectric thin film resonators formed over the substrate. Each of the plurality of the piezoelectric thin film resonators includes lower electrode provided on the substrate, a piezoelectric film provided on the lower electrode, and an upper electrode provided on the piezoelectric film and opposed to the lower electrode through the piezoelectric film. Each of the piezoelectric thin film resonators is partly supported by the substrate and extends above the substrate to form a cavity between the substrate and each lower electrodes. The cavity continuously extending under the plurality of the piezoelectric thin film resonators.

Abstract: A piezoelectric thin film resonator of the present has a substrate 1, an intermediate layer 7 disposed on the substrate 1 and is formed of an insulator, a lower electrode 3 disposed on the intermediate layer 7, a piezoelectric film 4 disposed on the lower electrode 3, and an upper electrode 5 disposed on a position facing the lower electrode 3 with the piezoelectric film 4 interposed therebetween, in which, in a resonant region 8 where the lower electrode 3 and the upper electrode 5 face each other, a space 6 is formed in the substrate 1 and the intermediate layer 7 or between the lower electrode 3 and the intermediate layer 7 and the region of the space 6 is included in the resonant region 8. With the structure, the dissipation of the vibrational energy to the substrate from the resonance portion can be suppressed, thereby improving the quality factor.

Abstract: A piezoelectric thin-film resonator includes a substrate, a lower electrode provided on the substrate, a piezoelectric film provided on the lower electrode and an upper electrode that is located opposite the lower electrode across at least a part of the piezoelectric film. A mass load film is provided on the upper electrode. The mass load film includes a plurality of concave or convex patterns in at least a region that faces the lower electrode. The plurality of concave or convex patterns are densely arranged in a central portion of the region and are sparsely arranged in a peripheral portion of the region.

Abstract: A filament lamp is provided. The filament lamp includes: a long light emitting section including a plurality of filaments aligned with one another in an axial direction of the light emitting section, wherein electric power is independently supplied to each of the filaments; a sealing section that seals the light emitting section, including: a first sealing section provided at one end of the light emitting section; and a second sealing section provided at the other end of the light emitting section; a plurality of metal foils embedded in the sealing section; a plurality of external leads each connected to a corresponding one of the metal foils and extending from the sealing section to the outside; and a plurality of glass pipes each provided on the sealing section so as to cover a corresponding one of the external leads.

Abstract: For providing a lamp lighting device and a filament lamp wherein a wire breakage of the filament lamp can be detected without an excessive consumption of power while the device as a whole is not enlarged, a filament lamp is provided comprising a light emission tube having at least one sealing portion and in the interior of which at least one filament is arranged, internal leads connected to both ends of said filament, metal foils for power supply provided in said at least one sealing portion of the light emission tube and connected to said internal leads, and external leads connected to said metal foils for power supply; wherein a metal foil for detection is provided in said sealing portion and is connected to one of a said internal lead and a said metal foil for power supply, and an external detection lead is provided at said metal foil for detection.

Abstract: A piezoelectric thin-film resonator includes a substrate, a lower electrode provided on the substrate, a piezoelectric film provided on the substrate and the lower electrode, an upper electrode provided on the piezoelectric film, and an additional pattern, a cavity being formed between the lower electrode and the substrate in a resonance portion in which the lower electrode and the upper electrode face each other through the piezoelectric film, the additional pattern being provided in a position that is on the lower electrode and includes an interface between the resonance portion and a non-resonance portion.

Abstract: 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.

Abstract: An acoustic wave device includes: a substrate; a lower electrode formed on the substrate; at least two piezoelectric films formed on the lower electrode; an insulating film located between the at least two piezoelectric films; and an upper electrode formed on the at least two piezoelectric films, wherein an outer periphery of an uppermost piezoelectric film out of the at least two piezoelectric films in a region in which the lower electrode and the upper electrode face each other is positioned further in than an outer periphery of the upper electrode.

Abstract: 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.

Abstract: An acoustic wave filter including piezoelectric thin film resonators, in which at least two of the piezoelectric thin film resonators including: a substrate; a piezoelectric film located on the substrate; a lower electrode and an upper electrode located across at least a part of the piezoelectric film; a mass load film for a frequency control located in a resonance region where the lower electrode and the upper electrode face each other, and having a shape different from that of the resonance region; and a temperature compensation film having a temperature coefficient of an elastic constant opposite in sign to that of the piezoelectric film, at least a part of the temperature compensation film being located between the lower electrode and the upper electrode in the resonance region, and areas of mass load films of said at least two of the piezoelectric thin film resonators are different from each other.

Abstract: 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.

Abstract: An electronic circuit includes a plurality of duplexers that are coupled to an antenna terminal and have a pass band different from each other and a plurality of acoustic wave filters that are respectively coupled between the antenna terminal and the plurality of the duplexers, wherein filter characteristics of a first acoustic wave filter of the plurality of the acoustic wave filters are set so as to allow passage of a signal in both a pass band for transmitting and a pass band for receiving of a first duplexer of the plurality of the duplexers that is coupled to the first acoustic wave filter and suppress passage of a signal in both a pass band for transmitting and a pass band for receiving of a second duplexer of the plurality of the duplexers that is different from the first duplexer.

Abstract: A piezoelectric thin-film resonator includes a substrate, a lower electrode provided on the substrate, a piezoelectric film provided on the lower electrode and an upper electrode that is located opposite the lower electrode across at least a part of the piezoelectric film. A mass load film is provided on the upper electrode. The mass load film includes a plurality of concave or convex patterns in at least a region that faces the lower electrode. The plurality of concave or convex patterns are densely arranged in a central portion of the region and are sparsely arranged in a peripheral portion of the region.

Abstract: A piezoelectric thin film resonator includes a substrate, a lower electrode provided on the substrate, a piezoelectric film provided on the lower electrode, and an upper electrode provided on the piezoelectric film. At least a portion of the upper electrode and that of the lower electrode oppose each other through the piezoelectric film, and at least a portion of the periphery of the upper electrode is reversely tapered.

Abstract: A method of producing a piezoelectric thin film resonator is provided. A sacrificial layer is formed on a part of the piezoelectric film. The sacrificial layer is patterned, and thereafter an upper electrode is formed on the piezoelectric layer. The method further includes removing the sacrificial layer formed on the piezoelectric layer; and patterning the piezoelectric film. In the step of removing the sacrificial layer, the sacrificial layer is removed such that at least a portion of the periphery of the upper electrode has a reversely tapered shape that reflects the tapered portion of the sacrificial layer, and in the step of patterning the piezoelectric film, the piezoelectric film is removed such that a lower end of the reversely tapered periphery of the upper electrode is placed so as to coincide with or to be in the vicinity of an end portion of the patterned piezoelectric film.

Abstract: A piezoelectric thin-film resonator includes a substrate, a lower electrode provided on the substrate, a piezoelectric film provided on the substrate and the lower electrode, an upper electrode provided on the piezoelectric film, and an additional pattern, a cavity being formed between the lower electrode and the substrate in a resonance portion in which the lower electrode and the upper electrode face each other through the piezoelectric film, the additional pattern being provided in a position that is on the lower electrode and includes an interface between the resonance portion and a non-resonance portion.

Abstract: An acoustic wave device including: a substrate; a piezoelectric film formed on the substrate; an lower electrode provided on a first surface of the piezoelectric film; an upper electrode provided on a second surface of the piezoelectric film opposite to the first surface; and a mass loading film having a first pattern and a second pattern in a resonance portion in which the lower electrode and the upper electrode face each other through the piezoelectric film, the first pattern having portions and the second pattern having portions interlinking the portions of the first pattern.