A radio frequency apparatus includes a power amplifier circuit, a signal coupling circuit, an extraction circuit, and a harmonic filter circuit. The power amplifier circuit is configured to amplify a differential signal to output a to-be-filtered signal. The signal coupling circuit includes a primary side inductor and a secondary side inductor. The signal coupling circuit is configured to convert the to-be-filtered signal received by the primary side inductor into a single-ended signal outputted from the secondary side inductor. The extraction circuit has a center tap. The extraction circuit is configured to inductively couple to the primary side inductor and output a common mode signal from the center tap. The harmonic filter circuit is configured to perform a harmonic filtering on the single-ended signal according to the common mode signal, such that the secondary side inductor of the signal coupling circuit outputs a filtered signal.

An inductor device includes a first inductor, a second inductor, and at least one switch circuit. The second inductor is arranged to enclose the first inductor, and use a topmost layer metal to resist external interference for the first inductor. The at least one switch circuit is coupled to the second inductor, and is arranged to receive at least one control voltage, wherein the at least one control voltage is arranged to adjust conduction degree of the at least one switch circuit.

A direct-current voltage conversion circuit having on/off control with a dead-time period performed alternately on a first switch and a second switch included in a direct-current voltage conversion circuit. When alternating current flows in a series circuit part including two transformers magnetically independent, current flows in an output circuit including a secondary side of one transformer, and energy is accumulated in the other transformer. The permeabilities of the magnetic cores in the first and second transformers is between 15 and 120.

Asymmetric AC to DC autotransformer for turboelectric propulsion, and associated systems and methods are described herein. In one embodiment, an asymmetric AC to DC autotransformer includes: a first coil, a second coil and a third coil of a delta winding Each coil is energized at its corresponding input phase. A first plurality of correction windings coupled to the first coil, a second plurality of correction windings coupled to the second coil, and a third plurality of correction windings coupled to the third coil. A bridge rectifier having a plurality of rectifiers is coupled to respective individual correction windings. Phases of the individual correction windings are asymmetric such that individual phase voltages are controlled relative to the opposite input phase. Voltages are unbalanced relative to neutral.

Asymmetric AC to DC autotransformer for turboelectric propulsion, and associated systems and methods are described herein. In one embodiment, an asymmetric AC to DC autotransformer includes: a first coil, a second coil and a third coil of a delta winding Each coil is energized at its corresponding input phase. A first plurality of correction windings coupled to the first coil, a second plurality of correction windings coupled to the second coil, and a third plurality of correction windings coupled to the third coil. A bridge rectifier having a plurality of rectifiers is coupled to respective individual correction windings. Phases of the individual correction windings are asymmetric such that individual phase voltages are controlled relative to the opposite input phase. Voltages are unbalanced relative to neutral.

An inductor unit includes a conductive structure, a first magnetic element and an insulating layer. The conductive structure has a bottom conductive layer, a top conductive layer, and a first side conductive layer extending from the bottom conductive layer to the top conductive layer. The first magnetic element is disposed on the bottom conductive layer of the conductive structure. The insulating layer is disposed on the bottom conductive layer of the conductive structure, wherein the insulating layer covers and surrounds the first magnetic element. The circuit structure including the inductor unit and the methods for manufacturing the same are also provided.

An inductor unit includes a conductive structure, a first magnetic element and an insulating layer. The conductive structure has a bottom conductive layer, a top conductive layer, and a first side conductive layer extending from the bottom conductive layer to the top conductive layer. The first magnetic element is disposed on the bottom conductive layer of the conductive structure. The insulating layer is disposed on the bottom conductive layer of the conductive structure, wherein the insulating layer covers and surrounds the first magnetic element. The circuit structure including the inductor unit and the methods for manufacturing the same are also provided.

A resonant induction wireless power transfer coil assembly designed for low loss includes a wireless power transfer coil, a non-saturated backing core layer adjacent the wireless power transfer coil, an eddy current shield, a gap layer between the backing core layer and the eddy current shield, and an enclosure that encloses the wireless power transfer coil, backing core layer, gap layer and eddy current shield. The gap layer has a thickness in a thickness range for a given thickness of the backing core layer where eddy current loss in the eddy current shield is substantially flat over the thickness range. A thickness of the backing core layer and a thickness of the gap layer are selected where a total power loss comprising power loss in the backing core layer plus eddy current loss over the gap layer is substantially minimized.

The disclosure provides an internal thermal fault diagnosing method for an oil-immersed transformer based on DCNN and image segmentation, including: 1) dividing an internal area of a transformer, and using fault areas and normal status as labels of DCNN; 2) through lattice Boltzmann simulation, randomly obtaining multiple feature images of the internal temperature field distribution of the transformer under normal and various fault state modes, and the fault area serves as a label to form the underlying training sample set; 3) obtaining historical monitoring information of the infrared camera or temperature sensor, and forming its corresponding fault diagnosis results into labels; 4) combining all monitoring information contained in each sample into one image, and then extracting the same monitoring information from the samples in the sample set to form a new image; 5) segmenting image sample and then inputting the same into DCNN for training to obtain diagnosis results.

An electromagnetic device for converting energy comprises: a ferromagnetic core of essentially planar shape and delimited by a peripheral contour; a primary winding and a secondary winding formed by primary turns and secondary turns, respectively. The device includes, arranged against the peripheral contour, a first block and a second block and a ferromagnetic material, and has a magnetic permeability lower than that of the ferromagnetic core. At least one primary turn and/or at least one secondary turn is formed around or passing through the first block and/or the second block to form, respectively, a first leakage inductance and/or a second leakage inductance.