Abstract: An amplifier device includes an amplifier including cascade-connected power amplifiers in a plurality of stages and a bias circuit configured to supply bias currents to the amplifier. A bias current supplied to a power amplifier in the first stage of the power amplifiers in the plurality of stages exhibits a positive temperature characteristic. A bias current supplied to a power amplifier in the final stage exhibits a negative temperature characteristic.

Abstract: A change in potential at a ground terminal is suppressed. A radio frequency module includes a mount board, a first circuit element, a second circuit element, a signal terminal (an antenna terminal, a signal input terminal, or a signal output terminal) for a radio frequency signal, and a block terminal. The mount board has a first principal surface and a second principal surface facing each other. The first circuit element is mounted on the first principal surface of the mount board. The second circuit element is mounted on the second principal surface of the mount board. The signal terminal (the antenna terminal, the signal input terminal, or the signal output terminal) is disposed on the second principal surface of the mount board. The block terminal is disposed on the second principal surface of the mount board. The block terminal includes a plurality of ground terminals.

Abstract: A multilayer resin substrate includes a base material including stacked resin layers including an opening resin layer, a conductor pattern, and an interlayer connection conductor. A concave portion is provided in the base material. The opening resin layer is closer to a first main surface than other resin layers. The concave portion includes a first opening portion provided by a cutting process from one surface of the opening resin layer, and another resin layer. The interlayer connection conductor is provided by filling a conductor in a second opening portion provided by a cutting process from an opposite surface of the opening resin layer. The end portion of the one surface of the first opening portion is not in contact with the conductor pattern.

Abstract: In a coil device, a first coil includes a common terminal side first coil conductor connected to a ground terminal, an intermediate first coil conductor, and an input/output terminal side first coil conductor connected to a first input/output terminal, and a second coil includes a common terminal side second coil conductor connected to the ground terminal, an intermediate second coil conductor, and an input/output terminal side second coil conductor connected to a second input/output terminal. The input/output terminal side first coil conductor is located between the intermediate second coil conductor and the input/output terminal side second coil conductor, and the input/output terminal side second coil conductor is located between the intermediate first coil conductor and the input/output terminal side first coil conductor.

Abstract: A coil component is capable of suppressing permeation of liquid or gas into a magnetic portion and increasing mechanical strength of the magnetic portion. A coil component includes a magnetic portion including soft magnetic metal particles having an insulating oxide layer on a surface thereof, with the soft magnetic metal particles being bonded to each other with the insulating oxide layer interposed therebetween; and a coil portion provided inside or on the surface of the magnetic portion. A mixture containing a resin and inorganic particles is disposed between the soft magnetic metal particles.

Abstract: An acoustic wave filter includes series arm resonators and parallel arm resonators each including an acoustic wave resonator including an IDT electrode including a pair of comb-shaped electrodes each including electrode fingers and a busbar electrode. An electrode finger connected to neither of the busbar electrodes of the pair of comb-shaped electrodes is a floating withdrawal electrode, and of all the electrode fingers of the pair of comb-shaped electrodes, the electrode finger that is connected to a same busbar electrode to which the electrode fingers on both sides thereof are connected is a polarity-reversing withdrawal electrode, and, of the series arm resonators, the series arm resonator having a lowest anti-resonant frequency includes an IDT electrode including the floating withdrawal electrodes, and the series arm resonator includes an IDT electrode including the polarity-reversing withdrawal electrodes.

Abstract: An electronic component includes a substrate and side wires. The substrate includes a first major surface, a second major surface, and a side surface. The side wires are on the side surface of the substrate and spaced apart from each other in a direction along an outer periphery of the substrate when viewed in plan in a thickness direction of the substrate. At least a portion of each of the side wires is provided indirectly on the side surface of the substrate. The electronic component further includes an electrically insulating layer interposed between the side surface of the substrate and the at least a portion of each of the side wires. Each of the side wires includes a bent portion bent when viewed in plan in the thickness direction of the substrate.

Abstract: A vibrating device includes a translucent cover, an ejector to eject a liquid onto the surface of the translucent cover, and a first vibrating portion to vibrate the translucent cover at a vibration acceleration of larger than about 8.0×105 m/s2 and equal to or smaller than about 21.0×105 m/s2.

Abstract: A directional coupler includes a main line, a sub-line, a coupling terminal, a terminal circuit, a first switching circuit, and a second switching circuit. The first switching circuit and the second switching circuit respectively connects the first end and the second end of the sub-line alternately to the coupling terminal and to the terminal circuit. The first switching circuit connects the first end to the coupling terminal at a time that differs from a time at which the first switching circuit disconnects the first end from the terminal circuit. The first switching circuit disconnects the first end from the coupling terminal at a time that differs from a time at which the first switching circuit connects the first end to the terminal circuit.

Abstract: A multilayer coil component includes an insulator portion, a coil in the insulator portion and including coil conductor layers electrically connected together, and an outer electrode on a surface of the insulator portion and electrically connected to the coil. The multilayer coil component has a void at a boundary between one main surface of each coil conductor layer and the insulator portion. At least one of the coil conductor layers includes extended and winding portions, and is connected to the electrode via the extended portion. Viewing the multilayer coil component in plan view in a stacking direction, an end of the void at the extended portion facing the electrode to which the extended portion is connected is closer to the electrode than is an end, facing the electrode, of the void at the coil conductor layer to which the extended portion is adjacent in the stacking direction.

Abstract: An electronic component includes a multilayer body including inner electrodes and dielectric layers that are alternately stacked, and outer electrodes that are electrically connected to the inner electrodes. The multilayer body includes first and second main surfaces opposite each other in a stacking direction, first and second side surfaces opposite each other in a width direction, and first and second end surfaces opposite each other in a length direction. At least one of the outer electrodes is located on at least one of the first side surface or the second side surface of the multilayer body and is directly connected to the inner electrodes at positions spaced away from the at least one of the first side surface or the second side surface toward the inside of the multilayer body.

Abstract: A battery includes a positive electrode, a negative electrode, and an electrolyte, and the positive electrode includes a substituted barium titanate.

Abstract: An acoustic wave device includes an antenna terminal, a signal terminal, and a plurality of resonators that are provided on a piezoelectric substrate. The plurality of resonators include a plurality of series arm resonators on a series arm, and the duty of an IDT electrode of the series arm resonator closest to the antenna terminal among the plurality of series arm resonators is smaller than the duty of an IDT electrode of at least one series arm resonator among the other series arm resonators.

Abstract: A pump device includes a piezoelectric pump, a piezoelectric pump, and a driving circuit. The piezoelectric pump is driven at a first frequency when singly driven. The piezoelectric pump is driven at a second frequency when singly driven. The driving circuit drives the piezoelectric pump and the piezoelectric pump at the same driving frequency.

Abstract: A cover for covering an oral device that includes a first sheet member made of a first resin, and a second sheet member made of a second resin and facing the first sheet member, wherein when a first direction is a direction along a surface of the first sheet member and a second direction is a direction along the surface of the first sheet member and orthogonal to the first direction, the first sheet member and the second sheet member are joined to each other in a bag shape so as to define an opening at a first side in the first direction. A protruding portion protrudes from the second sheet member and past an outer edge of the first sheet member at the opening in the first direction.

Abstract: An antenna module includes an antenna substrate and a feed circuit. The antenna substrate has an upper surface and a lower surface, and a radiating element having a flat plate shape is arranged in the antenna substrate. The feed circuit 105 is mounted on the lower surface of the antenna substrate and supplies a radio frequency signal to the radiating element. The antenna substrate includes a dielectric substrate on which the radiating element is arranged, a ground electrode, a feed wiring, and carbides. The ground electrode is arranged between the radiating element and the lower surface in the dielectric substrate. The feed wiring transmits the radio frequency signal supplied from the feed circuit to the radiating element. The carbides are disposed on at least a part of a side surface connecting the upper surface and the lower surface in the dielectric substrate.

Abstract: An inductor including an element body containing metal magnetic powder and resin and having a coil conductor that has a winding portion, an extended portion extended from the winding portion, and an outer electrode connection portion leading to the extended portion and connected to an outer electrode and is embedded in the element body; and an element body coat covering a surface of the element body. The outer electrode is formed on a surface of the element body and connected to the outer electrode connection portion, in which the outer electrode connection portion has a region covered with the element body coat and a region connected to the outer electrode on the surface of the element body.

Abstract: A tactile and proximity sensor includes a light source, a light receiver, an elastic structure, and a reflecting mirror. The light source emits light. The light receiver receives light and generates a signal indicating a result of reception of the light. The elastic structure includes an elastic body deformable in response to an external force and includes a reflecting portion to reflect light and transmitting portions to transmit light. The reflecting mirror faces the light source to guide the light from the light source to the reflecting portion and the transmitting portion.

Abstract: A composite capacitor that includes a first capacitor and a second capacitor. Each of plural first columnar conductors and each of plural second columnar conductors have a nano-size outer diameter. The composite capacitor includes a connecting conductor layer and a reinforcement conductor. The reinforcement conductor is located between a first counter electrode layer and a second counter electrode layer of the first capacitor and the second capacitor, respectively, and is connected to each of the first counter electrode layer, the second counter electrode layer, and the connecting conductor layer. The material forming the reinforcement conductor is the same as each of the first counter electrode layer and the second counter electrode layer and is different from the material forming the connecting conductor layer.

Abstract: A power amplifier unit includes a power amplifier circuit that amplifies a radio-frequency input signal, a first impedance matching circuit that performs impedance matching for an output signal of the power amplifier circuit, a second-order harmonic termination circuit on an output side of the first impedance matching circuit and that reflects at least part of even-ordered and odd-ordered harmonics contained in a signal input from the first impedance matching circuit to output the at least part of the harmonics from an input terminal as a radio-frequency signal and outputs a radio-frequency signal containing a fundamental and the remainder of the harmonics from an output terminal, and a filter that is on a subsequent stage of the second-order harmonic termination circuit, that attenuates at least part of the even-ordered and odd-ordered harmonics, and that outputs a radio-frequency signal including the fundamental and the remainder of the even-ordered and odd-ordered harmonics.