An 8-shaped inductive coil device that includes a first and a second spiral coils and a connection segment structure is provided. The first spiral coil includes first metal segments and crossing connection segments disposed at a first and a second metal layers respectively and includes first connection terminals. The second spiral coil includes second connection terminals. The connection segment structure electrically couples the first and the second connection terminals. The first and the second spiral coils are disposed along an imaginary line passing through a central region of each of ranges surrounded by the first and the second spiral coils. The connection segment structure and the crossing connection segments electrically couple the part of the first metal segments substantially vertical to the imaginary line, and the connection segment structure and the crossing connection segments are disposed substantially on the imaginary line.

Embodiments disclosed herein include a package core. In an embodiment, the package core comprises a core substrate, a first opening through the core substrate, a second opening through the core substrate and adjacent to the first opening, and a first structure around the core substrate between the first opening and the second opening. In an embodiment, the first structure is electrically conductive. The package core may further comprise a second structure around the core substrate outside of the first opening and the second opening, where the second structure is electrically conductive.

A transformer of the symmetric-asymmetric type includes comprising a primary inductive circuit and a secondary inductive circuit formed in a same plane by respective interleaved and stacked metal tracks. A first crossing region includes a pair of connection plates facing one another, with each connection plate having a rectangular shape that is wider than the metal tracks, and diagonally connected to tracks of the secondary inductive circuit.

A transformer includes a magnetic core, a first coil unit and a second coil unit. The first coil unit is disposed within the magnetic core and includes a laminated board having layers laminated therein and conductive patterns. Respective ones of the conductive patterns are disposed on the laminated layers. The second coil unit includes a conductive wire spaced apart from the conductive patterns of the laminated board by an insulating distance. The conductive wire includes a triple-insulated wire surrounded by three sheets of insulating paper to maintain the insulating distance from the conductive patterns.

A switched mode power supply is provided. The power supply includes a flyback converter with a GaN-based power semiconductor transistor and a planar transformer. The planar transformer includes a magnetic core and primary and secondary planar coil windings. The magnetic core has a lower core and an upper core. The lower core has at least three projections including a central projection and two peripheral projections. The central projection has a height extending above the heights of the two peripheral projections and accepts the primary and the secondary planar coil windings which surround the central projection. The upper core includes a recessed portion that receives the central projection of the lower core such that a gap is positioned between the central projection of the lower core and the recessed portion of the upper core when the two peripheral projections contact the upper core.

A connection system for exchanging electrical signals includes a first symmetrical connector and a second symmetrical connector. Each symmetrical connector has at least one magnetic core provided with at least one turn. The symmetrical connectors are produced in a substrate made of insulating material so as to form a half of a coupling transformer. At least one half of the coupling transformer of each connector is arranged opposite one another so as to be able to exchange a magnetic flux. The electrical signals are emitted by the first connector in the form of a magnetic flux, and the second connector generates the electrical signals on receiving the magnetic flux.

An inductor device includes a first trace, a second trace, a third trace, a fourth trace, and a double ring inductor. The first trace is disposed in a first area, and located on a first layer. The second trace is disposed in the first area, coupled to the first trace, and located on a second layer. The third trace is disposed in a second area, and located on the first layer. The fourth trace is disposed in the second area, coupled to the third trace, and located on the second layer. The double ring inductor is disposed on the first layer, located at outer side of the first trace and the third trace, and coupled to the first trace and the third trace.

Various examples of magnetic integration of matrix transformers with controllable leakage inductance are described. In one example, a transformer includes a magnetic core comprising a plurality of core legs and a leakage core leg. The leakage core leg is positioned among the plurality of core legs to control a leakage inductance of the transformer. The transformer also includes a planar winding structure. The planar winding structure includes a primary winding and a plurality of secondary windings. The primary winding and the plurality of secondary windings extend in a number of turns around the plurality of core legs, without a turn around the leakage core leg, to further control the leakage inductance of the matrix transformer.

A transformer chip of a signal transmitting device has a substrate, an element insulation layer, and a first transformer and a second transformer provided within the element insulation layer. The first transformer comprises a first coil, and a second coil positioned facing the first coil in the z direction. The second transformer comprises a first coil, and a second coil positioned facing the first coil in the z direction. The second coil of the first transformer and the second coil of the second transformer are electrically connected. The transformer chip comprises a back surface insulating layer provided on the back surface of the substrate.

A tunable inductor has a first magnetic core and a second magnetic core wound with a direct current (DC) winding and an alternating current (AC) winding. A first portion of the AC winding is wound around a first portion of the first magnetic core, and a second portion of the AC winding is wound around a first portion of the second magnetic core. The DC winding is wound simultaneously around the first magnetic core and the second magnetic core in a second portion that does not overlap the first portion of the first magnetic core and the second magnetic core. The DC winding is connected to a DC control circuit that applies a DC voltage to control permeability of the first magnetic core and the second magnetic core, which allows inductance value of the tunable inductor to be adjusted.