International audienceThis paper presents a new design of a planar transformer. Over the surface of a flat core, meander-type design was engraved, so that symmetrically adjusted primary and secondary coils, of the same meander-type, can fit into the engraved design. Primary and secondary coils were covered with another flat core consequently forming a compact planar transformer. Windings of primary and secondary coils are printed on both sides of PCB. Conductive stripes of a winding from upper and bottom layer are connected by vias. The transformer was analyzed when the primary and secondary coils were without a core and with a core. High frequency parameters of the transformer were obtained by finite element modeling software and Impedance Analyzer HP4194A in the frequency range from 50 kHz to 1 MHz. The transformer is intended to be used in DC-DC converters (for switching frequency up to several hundred kHz)

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International audienceIn this paper, planar printed-circuit board (PCB) transformers with different winding arrangements are presented. Three different arrangements of the primary and the secondary meander-type windings are designed and fabricated. The electrical parameters of the transformers for all three designs are analyzed and compared. A significant increase of inductance of the primary and the secondary winding is achieved with an appropriate meander-type winding arrangement. In the frequency range of interest, the inductance is approximately 145 nH for the first design, whereas the inductance is approximately 1250 nH for the second and the third design. The coupling coefficient is 0.14 for the first design, whereas it is around 0.9 for the second and the third design. The transformer of the proposed design is to be used in low-power DC/DC converters; therefore, the core with high permeability Ferroxcube 3C90 was chosen. In addition, the transformers of the same winding arrangements were tested with Ferroxcube 3F3 core

In this paper design, modeling and characterization of single and double coils, which consist of conductive layer embedded in the soft ferrite material, are described. These surface-mount components, comprising of a cofired multilayered ferrite and coil, have been developed in the ceramic coprocessing technology. A simple analytical model of proposed structures is presented. This model is very suitable for circuit simulations and for prediction of frequency characteristics of considered inductors. The inductance and impedance of coils embedded in low permeability or high permeability ferrite material are calculated and compared. Also, these suppressors were experimentally tested in the frequency range 1 MHz-3 GHz using an Agilent 4287 A RF LCR meter. The calculated results were in good agreement with the measured ones.