The high frequency transformer design are starting from the core, and in the case of low magnetic fields are generally used soft magnetic material, because it has a high permeability, low coercivity, high resistivity magnetic guide rate, when a certain number of turns, through the magnetizing current can not withstand high applied voltage, and therefore, the output at a certain power requirements, reduce the core volume. low coercivity magnetic core, hysteresis area small, the iron loss is small. high resistivity, the eddy current is small, a small iron loss. ferrite material is a composite oxide sintered compact, high resistivity, suitable for use at high frequencies, but the value Bs is relatively small, often use in switching power supplies.
 
With the development of the overall structure of the high-frequency transformer, the transformer coil structure has followed the development of the main direction of development is a planar coil, sheet and film winding coils, which also includes a multi-layer structure. Selection of materials of various coil structure, there are some new development.
 
Three-dimensional structure of the high-frequency transformer coil wire material on account of skin effect and proximity effect, multi-stranded (Leeds line), sometimes with flat copper wire and copper. Thermal insulation material used high grade materials to increase the allowable temperature rise and reduce coil size, the use of double and triple insulated wire, can reduce the size of the coil; planar coil leads and copper, in most cases, single and multiple layer printed circuit board manufacturing, there is also a certain pattern of copper foil, a plurality of folded. Insulating materials commonly used B-grade material.
 
Film structure of the coil wire copper, silver and gold films made comb, spiral, playgrounds and other graphics-shaped insulating material Class H and C-grade material. There is also a multilayer structure, or a combination of several multi-layered coil or several coils and several cores from overlapping. In short, the film is now being vigorously developed transformers high-frequency transformers, many of the structures are not stereotypes, perhaps, there will be many new coil structure.