Abstract: Provided are a 3D filter circuit and a 3D filter. The 3D filter circuit includes a multilayer structure. The multilayer structure includes at least two conductive layers and at least one organic dielectric layer. Each organic dielectric layer is disposed between different conductive layers. The multilayer structure is configured to form at least one capacitor.

Abstract: A band-pass filter includes a first inductor and a second inductor electromagnetically coupled to each other, a first ground terminal electrically connected to the first inductor, a second ground terminal electrically connected to the second inductor, and a stack for integrating the first inductor, the second inductor, the first ground terminal, and the second ground terminal. The first ground terminal and the second ground terminal are each connected to a ground and are not electrically connected to each other in the stack.

Abstract: RF signal transmission devices for a base station antenna include a printed circuit board which has a dielectric layer, a metal pattern layer on a first main surface of the dielectric layer, and a ground layer on a second main surface of the dielectric layer. The metal pattern layer has a transmission line deformation section for enhancing the ability to withstand surge current, and the ground layer comprises a groove that is configured to at least partially compensate for the change in the characteristic impedance due to the transmission line deformation section. The RF signal transmission device can achieve good characteristic impedance matching whilst enhancing the capacity to withstand surge current. In addition, the RF signal transmission device can improve PIM performance. The present disclosure also includes a phase shifter for a base station antenna and a base station antenna.

Abstract: A multi-layered resonator circuit structure and a multi-layered filter circuit structure. The multi-layered resonator circuit structure includes a multi-layered substrate, a plurality of resonators and a plurality of conductive components. The multi-layered substrate has a top surface, a bottom surface, and a ground layer. The top surface and the bottom surface face away from each other. The ground layer is located between the top surface and the bottom surface. A part of the plurality of resonators is/are disposed on the top surface. Another part of the plurality of resonators is/are disposed on the bottom surface. The plurality of conductive components is located in the multi-layered substrate. The plurality of resonators is electrically connected to the ground layer, respectively, via the plurality of conductive components.

Abstract: A filter device includes a multilayer substrate, an inductor, and a first open stub. The multilayer substrate includes a first wiring layer, a second wiring layer including a first reference electrode to which a reference potential is supplied, and a plurality of first dielectric layers between the first wiring layer and the second wiring layer. The inductor has one end coupled to a first terminal and another end coupled to a second terminal. A portion of the first open stub is provided in the first wiring layer, and the first open stub has one end coupled to the one end of the inductor and another open-circuited end. When the multilayer substrate is viewed in plan view in a stacking direction, a capacitor is formed by the first reference electrode and the first open stub that mutually overlap. A resonant circuit is formed by the capacitor and the inductor.

Abstract: A common line is connected between a common terminal and a common connection node. A first filter has a first pass band. A second filter has a second pass band. At least one of a first condition and a second condition is satisfied. The first condition is that in the first pass band any one of a first impedance of the common line alone viewed from the common terminal (P10) and a second impedance of the first filter viewed from the common connection node includes an inductive property and the other includes a capacitive property. The second condition is that in the second pass band one of the first impedance and a third impedance of the second filter viewed from the common connection node includes an inductive property and the other includes a capacitive property.

Abstract: A band-pass filter includes a first port, a second port, first to third high-pass filters provided between the first port and the second port in this order from a first-port side in a circuit configuration, and a low-pass filter provided between the second high-pass filter and the third high-pass filter in the circuit configuration. Each of the first to third high-pass filters forms an attenuation pole on a low-pass side of the passband. A frequency of the attenuation pole formed by the second high-pass filter is higher than a frequency of the attenuation pole formed by each of the first and third high-pass filters.

Abstract: Aspects of this disclosure relate to an acoustic wave device with transverse mode suppression. The acoustic wave device can include a piezoelectric layer, an interdigital transducer electrode, a temperature compensation layer, and a multi-layer mass loading strip. The mass loading strip has a density that is higher than a density of the temperature compensation layer. The mass loading strip can overlap edge portions of fingers of the interdigital transducer electrode. The mass loading strip can include a first layer for adhesion and a second layer for mass loading. The mass loading strip can suppress a transverse mode.

Abstract: A filter includes a piezoelectric film, an acoustic wave resonator including a functional electrode on the piezoelectric film, a capacitor connected in parallel to the acoustic wave resonator, and a resonator electrically connected to the acoustic wave resonator. The functional electrode includes first and second busbars facing each other and first and second electrodes respectively connected to the first and second busbars. The filter further includes a connection electrode on the piezoelectric film and electrically connecting the capacitor and the second busbar to each other. The capacitor includes the first busbar, an insulation film on the first busbar, and a capacitance electrode on the insulation film and that is electrically insulated from the first busbar.

Abstract: A communication system includes a transmission unit configured to output a signal, an attenuation unit configured to attenuate the signal output from the transmission unit, a first coupler having one end portion being connected to the transmission unit via the attenuation unit, a termination unit that is connected to the other end portion of the first coupler, and a second coupler configured to input a signal to the first coupler using at least one of electric field coupling and magnetic field coupling, wherein the first coupler or the second coupler is configured to be movable so that a relative position between the first coupler and the second coupler changes.

Abstract: Aspects of the disclosure relate to devices, wireless communication apparatuses, methods, and circuitry implementing filters with electroacoustic vertical coupling. One aspect is a filter comprising a piezoelectric substrate having a first piezoelectric surface and a second piezoelectric surface opposite the first piezoelectric surface. The filter further comprises a first electroacoustic resonator comprising a first interdigital transducer (IDT) disposed on or over the first piezoelectric surface of the piezoelectric substrate and a second electroacoustic resonator comprising a second IDT disposed on or over the second piezoelectric surface of the piezoelectric substrate. The second electroacoustic resonator is electrically coupled to the first electroacoustic resonator in series or in parallel.

Abstract: A filter device includes a dielectric substrate, first and second ground electrodes connected to a ground terminal, and resonators between the ground electrodes and electromagnetically coupled to each other. The ground electrodes are at different positions in a normal direction of the dielectric substrate. Each of the resonators includes a first capacitor electrode partially overlapping with the first ground electrode in plan view of the dielectric substrate, a second capacitor electrode partially overlapping with the second ground electrode in plan view of the dielectric substrate, and a via connecting the capacitor electrodes. The resonators include a first resonator connected to an input terminal, a second resonator connected to an output terminal, and a third resonator between the first and second resonators. Shunt electrodes are connected to the via and the ground terminal in the first and second resonators, respectively.

Abstract: A balun circuit includes a first transformer comprising a first inductor and a second inductor, the first inductor having an electrical value different than the second inductor, a second transformer comprising a third inductor and a fourth inductor, the third inductor having an electrical value different than the fourth inductor, the first inductor connected to a positive terminal of a balanced port, the third inductor connected to a negative terminal of the balanced port, the second inductor connected to an unbalanced port and the fourth inductor connected to a node.

Abstract: An apparatus is disclosed for implementing a microacoustic filter with a cavity stack. In an example aspect, the apparatus includes a microacoustic filter with an electrode structure, a cavity stack, a buffer layer, and a piezoelectric layer. The cavity stack comprises a conductive layer, a substrate layer, and at least two pillars extending past a plane defined by a surface of the substrate layer and towards the conductive layer to form a cavity between the substrate layer and the conductive layer. The buffer layer is disposed between the conductive layer of the cavity stack and the electrode structure. The piezoelectric layer is disposed between the buffer layer and the electrode structure.

Abstract: An acoustic wave device includes a support substrate including a cavity portion and a support portion, a piezoelectric film on the support portion and including a first and second main surfaces, a functional electrode on the first main surface, and a heat dissipation film on at least one of the first and second main surfaces and includes a semiconductor or an insulator. The functional electrode includes at least one pair of first and second electrodes. When a thickness of the piezoelectric film is dx and a middle-to-middle distance between the first and second electrodes is p, dx/p is about 0.5 or less. The heat dissipation film overlaps at least a portion of the support portion in plan view. A thermal conductivity of the heat dissipation film is higher than a thermal conductivity of the piezoelectric film, and a thickness of the heat dissipation film is less than the thickness of the piezoelectric film.

Abstract: A filter device, method of manufacture and use thereof. The filter device comprises a foil-wound inductor formed by a first conductive foil strip having a first terminal and a second terminal, the first conductive foil strip wound around a core to form a plurality of winding layers such that the first terminal is proximate the core and the second terminal is located at the outermost winding layer, and a continuous dielectric insulating layer between the plurality of layers of the first conductive foil strip; and, a tunable capacitor formed by a second conductive foil strip at least partially encircling the outermost layer of the foil-wound inductor and a dielectric insulating layer disposed therebetween, the second conductive foil strip having a portion that can be trimmed to alter a capacitance between the second conductive foil strip and the first or second terminal of the foil-wound inductor.

Abstract: A filter device includes first to third resonators. Each of the first to third resonators includes a first line part and a second line part electrically connected to the first line part and having an impedance smaller than an impedance of the first line part. The impedance ratio in at least one of the first to third resonators is 0.3 or smaller. The shape of each of the second line part of the first resonator and the second line part of the second resonator is long in a direction orthogonal to a stacking direction and crossing the longitudinal direction of the second line part of the third resonator.

Abstract: A directional coupler includes a main line, a sub line electromagnetically coupled to the main line, a coupling output terminal connected to one end of the sub line, a filter connected between the one end of the sub line and the coupling output terminal, and a filter with a pass band higher than a pass band of the filter. One end of the filter is connected to the coupling output terminal. Another end of the filter is terminated.

Abstract: A bulk acoustic wave (BAW) device comprises a piezoelectric layer disposed between a first electrode layer and a sandwich electrode. The sandwich electrode includes a first layer of a first material having a first acoustic impedance and a second layer of a second material having a second acoustic impedance that is less than the first acoustic impedance of the first layer. The second layer of the sandwich electrode having the lower acoustic impedance is disposed between the first layer and the piezoelectric layer. The sandwich electrode combined with the piezoelectric layer and first electrode can cause the BAW device to resonate at a frequency whose wavelength corresponds to an acoustic cavity length of the BAW device, depending on an acoustic mirror included on one side of the BAW device. In one example, the acoustic cavity length is about 1.5 times of the resonant frequency wavelength.

Abstract: A capacitive element includes a piezoelectric substrate, a first electrode finger extending towards a positive side in a first direction, and a second electrode finger disposed facing and spaced apart from the first electrode finger in a second direction intersecting the first direction, extending towards a negative side in the first direction, and connected to a different potential from the first electrode finger. The first electrode finger includes a first portion extending in the first direction and a second portion extending from the first portion, through a first step portion, and at a different position in the second direction from the first portion. The second electrode finger includes a third portion disposed facing the second portion and extending in the first direction, and a fourth portion extending from the third portion through a second step portion, extending from the second portion in the first direction, and facing the first portion.