A filter structure includes a capacitive device and an inductive device. The capacitive device includes a ground plane in a first metal layer of an integrated circuit (IC) package, a plate in a second metal layer of the IC package, and a dielectric layer between the ground plane and the plate. The inductive device includes first and second conductive paths in a third metal layer of the IC package, each of the first and second conductive paths is electrically connected to the plate and has a width w, the first and second conductive paths are separated by a spacing s, and a ratio s/w has a value ranging from 1 to 2.

A filter device includes a first port, a second port, a first high-pass filter, a first low-pass filter, and a stack. The first high-pass filter includes a first inductor. The first low-pass filter includes a first inductor. At least one second conductor layer constituting the first inductor of the first low-pass filter is located between at least one first conductor layer constituting the first inductor of the first high-pass filter and a ground conductor layer in a stacking direction.

An electronic component includes a first and second inductor forming sections integrated with a stack, and a connection conductor layer connecting the first and second inductor forming sections inside the stack. In the first inductor forming section, two first through hole lines are connected to a wide portion of an inductor conductor layer, and two second through hole lines are connected to a narrow portion of the inductor conductor layer. In the second inductor forming section, two first through hole lines are connected to a wide portion of an inductor conductor layer, and two second through hole lines are connected to a narrow portion of the inductor conductor layer.

A glass core multilayer wiring board includes a glass substrate, a through electrode, a first layer structure, and a second layer structure. A through hole has a diameter decreasing from a first surface toward a second surface. The through electrode is along a side wall of the through hole. The first layer structure is on the first surface and the second layer structure is on the second surface. The second layer structure closes an opening in the second surface defining a bottom section. The through electrode has: a first layer on part of the side wall and on part or all of the bottom section of the through hole closing the opening of the through hole, a second layer covering the first layer, the side wall of the through hole exposed, and the bottom section, and a third layer is located on the second layer.

A communication system where a central node (base-station or access point) communicates with multiple clients in its neighbourhood using transparent immediate beam-forming. Resource allocation and channel access is such that the central node does not necessarily know when each client starts its transmission. Receive beam-forming in such a system is not possible, as beam-forming coefficients for each client should be selected according to the particular channel realization from that client to the central node. Each client is detected early in its transmission cycle, based on either a signature that is part of the physical characteristics unique to that client, or based on a signature that is intentionally inserted in the clients' signal, and accordingly adjusts its beam-forming coefficients.

A circuit board has a glass core in which a through hole is formed, and a conductor pattern is formed on an inner peripheral wall of the through hole and a surface of the glass core to form a circuit element including a solenoid coil element and a capacitor element. Accordingly, a low-cost and compact circuit board capable of supporting high-capacity communication for thin mobile communication devices such as smartphones can be provided. Since the circuit board can be electrically connected to at least one of the electronic components such as a switch, an amplifier, and a filter via one terminal, and can be electrically connected to a mother board via another terminal, it has integrated functions, and can be suitably used for thin mobile communication devices such as smartphones.

A filter element includes series inductors connected in series to a signal path, shunt inductors shunt-connected between the signal path and ground, and a capacitor connected in series to the shunt inductors. The shunt inductors include first and second shunt inductors connected in parallel to each other. Conductive patterns of the capacitor are overlapped with coil opening portions of the series inductors and the shunt inductors viewed from a lamination direction. The capacitor is sandwiched between the first shunt inductor and the second shunt inductor in the lamination direction of insulating layers and the conductive patterns.

Disclosed herein is a coil component that includes a first conductor layer having first and third planar spiral coils and second conductor layer having second planar spiral coil. The first planar spiral coil is positioned on an outer peripheral side of the third planar spiral coil. The first planar spiral coil has a pattern width larger than that of the third planar spiral coil. The second planar spiral coil is offset to the third planar spiral coil side in a plan view.

An LC filter includes a first electrode connected to a first via conductor between two ends of the first via conductor, a second electrode connected to a second via conductor between two ends of the second via conductor, a third electrode connected to a third via conductor between two ends of the third via conductor, and a fourth electrode connected to a fourth via conductor between two ends of the fourth via conductor. In a plan view viewed from the laminating direction, the second via conductor and the fourth via conductor are disposed on two sides of a virtual line connecting the first via conductor and the third via conductor, respectively. The second electrode faces the first electrode and the third electrode.

A capacitor is disposed on a substrate that is insulative. An inductor is disposed on the substrate. The inductor includes a conductor pattern having at least one end connected to the capacitor. The capacitor includes a dielectric film that mainly contains the same constituent element as a constituent element mainly contained in the substrate and at least two electrodes that face each other with the dielectric film interposed therebetween.