Abstract: A filter device includes a piezoelectric substrate including a high acoustic velocity material layer and a piezoelectric layer, and series and parallel arm resonators on the piezoelectric substrate. The parallel arm resonator includes a first IDT electrode on the piezoelectric substrate, and the series arm resonator includes a second IDT electrode on the piezoelectric substrate. First and second busbars of the first IDT electrode include opening formation regions, and an occupancy ratio of areas of openings in the first and second busbars of the first IDT electrode is greater than an occupancy ratio of areas of openings in first and second busbars of the second IDT electrode. In the first and second IDT electrodes, low acoustic velocity regions sandwich a central region. A high acoustic velocity region is provided in the opening formation region of each of the first and second busbars in the first IDT electrode.

Abstract: A radio frequency module includes a transmit filter of Band A and Band B, a transmit amplifier, and a switch circuit and can perform CA using a transmit signal of Band A and a receive signal of Band B, a transmit band of Band B including a receive band of Band C. The switch circuit includes a switch switching connection between a common terminal and a first selection terminal, a switch switching connection between the common terminal and a second selection terminal, and a switch switching connection between the second selection terminal and a third selection terminal. The common terminal is connected to the transmit amplifier. The first selection terminal is connected to the transmit filter of Band A. The second selection terminal is connected to the transmit filter of Band B. The third selection terminal is connected to a receive path of Band C.

Abstract: A CPAP device includes a housing. A suction port is provided in a top plate portion of a casing of the air blower. The air blower chamber has a facing wall portion facing the top plate portion with a distance therebetween. A wall portion defining the air blower chamber is provided with an introduction port for introducing external air. In a space between the facing wall portion and the top plate portion, a flow adjustment portion that partitions the space into flow paths arranged side by side around a rotation axis is provided. An outer end portion and an inner end portion of each of the flow paths in a direction orthogonal to the rotation axis are respectively constituted of a first open end and a second open end, the first open end and the second open end being open along the direction orthogonal to the rotation axis.

Abstract: An electronic component includes an electronic element and an interposer board. The electronic element includes a multilayer body and external electrodes at multilayer body end surfaces and connected to internal electrode layers. The interposer board includes board end surfaces, board side surfaces orthogonal to the board end surfaces, and board main surfaces orthogonal to the board end surfaces and the board side surfaces. One of the board main surfaces is in a vicinity of the electronic element and is joined with one of the multilayer body main surfaces in a vicinity of the interposer board. The interposer board is an alumina board. A maximum length of the interposer board is smaller than a length of the electronic element. A width of the interposer board is smaller than a width of the electronic element.

Abstract: Acoustic resonator devices and methods are disclosed. An acoustic resonator device includes a substrate having a surface and a single-crystal piezoelectric plate having front and back surfaces. An etch-stop layer is sandwiched between the surface of the substrate and the back surface of the piezoelectric plate, a portion of the piezoelectric plate and the etch-stop layer forming a diaphragm spanning a cavity in the substrate. An interdigital transducer (IDT) is formed on the front surface of the single-crystal piezoelectric plate with interleaved fingers of the IDT disposed on the diaphragm. The etch-stop layer is impervious to an etch process used to form the cavity. The etch-stop layer is a high thermal conductivity material selected from aluminum nitride, boron nitride, and diamond.

Abstract: An IC card communicates with a reader/writer, which is inductive read/write communication equipment, in a non-contact manner. The IC card includes a proximity detection circuit that detects a proximity state to the reader/writer, a near-field communication circuit, an electronic function circuit, an electricity storage device, and a power supply control circuit. The power supply control circuit controls, based on a detection result of the proximity detection circuit, power supply from the electricity storage device to the electronic function circuit. The IC card manages and controls presence/absence and timing of power supply from the electricity storage device to the electronic function circuit and effectively controls discharging of the electricity storage device and charging of the electricity storage device.

Abstract: There are disclosed acoustic resonators, filter devices, and methods of fabricating acoustic resonators and filter devices. An acoustic resonator includes a piezoelectric plate having front and back surfaces, the back surface attached to a surface of a substrate except for portions of the piezoelectric plate forming a diaphragm spanning a cavity in the substrate. A conductor pattern on the front surface includes an interdigital transducer (IDT) with interleaved fingers of the IDT disposed on the diaphragm. A plurality of holes is in the diaphragm, wherein each of the plurality of holes is configured to scatter spurious modes in the diaphragm.

Abstract: A multilayer coil component includes a multilayer body including insulating layers and having a first end face and a second end face, a first main surface and a second main surface, and a first side surface and a second side surface; a coil provided inside the multilayer body; a first outer electrode spreading from part of the first end face over part of the first main surface; and a second outer electrode spreading from part of the second end face over part of the first main surface. The laminating direction of the insulating layers and a direction of a coil axis of the coil are parallel to the first main surface as a mount surface. The coil has a length in a length direction from 85% to 94% of the length of the multilayer body in the length direction.

Abstract: A ferrite sintered body contains a main component and a sub component. The main component contains from 4 mol % to 13 mol % of Fe in terms of Fe2O3, from 47 mol % to 58 mol % of Zn in terms of ZnO, from 1 mol % to 4 mol % of Cu in terms of CuO, from 2 mol % to 8 mol % of Ni in terms of NiO, and from 28 mol % to 36 mol % of Si in terms of SiO2. The sub component contains, per 100 parts by weight of the main component, from 0.8 parts by weight to 3 parts by weight of Bi in terms of Bi2O3, from 0.003 parts by weight to 0.1 parts by weight of Mn in terms of Mn2O3, and from 0.003 parts by weight to 0.1 parts by weight of Cr in terms of Cr2O3.

Abstract: A multilayer inductor component includes an element body and an inductor wire. The element body has a bottom surface, and a surface parallel to the bottom surface is a top surface. The inductor wire has inductor conductors extending parallel to the bottom surface and via conductors extending along an orthogonal axis orthogonal to the bottom surface. The area of each inductor conductor when viewed in the direction along the orthogonal axis is a conductor area, and the number of the inductor conductors is N. In the direction along the orthogonal axis, a top surface-side conductor area that is a sum of conductor areas of the inductor conductor closest to the top surface to the N/2th inductor conductor is 1.1 times or more of a bottom surface-side conductor area that is a sum of conductor areas of the inductor conductor closest to the bottom surface to the N/2th inductor conductor.

Abstract: A power amplifier circuit that includes a carrier amplifier, peaking amplifiers, an input coil, an output coil, an input coil, an output coil, an output terminal to which one end of the output coil is connected, and ¼-wavelength transmission lines. The carrier amplifier is connected to one end of the input coil. The peaking amplifier is connected to one end of the ¼-wavelength transmission line. The peaking amplifier is connected to one end of the input coil. The peaking amplifier is connected to one end of the ¼-wavelength transmission line. The other end of the ¼-wavelength transmission line is connected to the other end of the input coil. The other end of the ¼-wavelength transmission line is connected to the other end of the input coil. One end of the output coil is connected to the other end of the output coil.

Abstract: An electronic card with biometric authentication function includes a communication antenna for short-range wireless communication, a wireless communication IC, a receiving coil, a resonant capacitor, a rectifying and smoothing circuit, a biometric sensor, and a biometric authentication circuit. The communication antenna and the receiving coil respond to a magnetic field in the same frequency band for the short-range wireless communication. The wireless communication IC performs short-range wireless communication. The receiving coil receives power from the magnetic field in the same frequency band for the short-range wireless communication. The biometric authentication circuit causes the biometric sensor to operate by using the power received from the receiving resonant circuit.

Abstract: This disclosure describes a micromechanical device comprising a first device part and a second device part. One of the first and second device parts is a mobile rotor and the other of the first and second device parts is a fixed stator. The micromechanical device further comprises a motion limiter which extends from the first device part to the second device part. The motion limiter comprises an elongated lever, and the motion limiter is configured to bring a stopper into contact with a counter-structure by rotating the elongated lever.

Abstract: A resonator includes a base; and at least three vibrating arms having first ends connected to a front end of the base and second ends that are open ends spaced away from the front end. Each vibrating arm includes an arm portion having a part that extends from the fixed end in a direction toward the open end with a constant width and a mass-adding portion that is connected to a tip of the arm portion and has a larger width than the arm portion. An interval between the mass-adding portions is larger than an interval between the arm portions for any two vibrating arms that are adjacent to each other.

Abstract: A connector includes a plurality of inner terminals and an outer terminal. The plurality of inner terminals are arrayed with intervals therebetween in a direction. The plurality of inner terminals are terminals that are connected to a ground potential. The outer terminal is disposed around the group of the plurality of arrayed inner terminals and are connected to a ground potential. The outer terminal includes side wall members that are shaped so as to extend in the direction and be parallel to the plurality of inner terminals. The inner terminals include connection parts that are connected to the side wall members.

Abstract: Acoustic resonator devices, filters, and methods are disclosed. An acoustic resonator includes a substrate and a lithium niobate (LN) plate having front and back surfaces and a thickness ts. The back surface is attached to a surface of the substrate. A portion of the LN plate forms a diaphragm spanning a cavity in the substrate. An interdigital transducer (IDT) is formed on the front surface of the LN plate with interleaved fingers of the IDT disposed on the diaphragm. The LN plate and the IDT are configured such that a radio frequency signal applied to the IDT excites a shear primary acoustic wave in the diaphragm. Euler angles of the LN plate are [0°, ?, 0° ], where 0???60°. A thickness of the interleaved fingers of the IDT is greater than or equal to 0.8 ts and less than or equal to 2.0 ts.

Abstract: A secondary battery including an electrode assembly including a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode, and an electrolyte encapsulated in an exterior body. The exterior body has a shape with a cutout portion in planar view thereof, and the exterior body has a seal portion along a peripheral edge portion thereof. The seal portion is folded in a thickness direction of the secondary battery to form a folded seal portion having an end on a cutout portion side to form a stopper portion for a board disposed in the cutout portion.

Abstract: A first amplifier circuit in a preceding stage, a second amplifier circuit in a subsequent stage, and a ground external connection terminal are disposed on a substrate. The first and second amplifier circuits each include bipolar transistors, capacitive elements for the respective bipolar transistors, and resistive elements for the respective bipolar transistors. The bipolar transistors each include separate base electrodes, that is, a first base electrode for radio frequency and a second base electrode for biasing. The bipolar transistors of the second amplifier circuit include emitter electrodes connected to the ground external connection terminal. The minimum spacing between the first base electrode and an emitter mesa layer of at least one of the bipolar transistors of the second amplifier circuit is greater than the minimum spacing between the first base electrode and am emitter mesa layer of each of the bipolar transistors of the first amplifier circuit.