Design, Modeling, and Analysis of a Compact Planar Transformer

This 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).