This paper presents a development and calculated rating of high-frequency transformer connect with switch-mode power supplies. These power supplies are used in various devices such as power personal communications services, television, DVD players and charge mobile phones Thus, increasing power density and decreasing cost are still the main factors in designing a switch-mode power supply. Magnetic elements represent a great amount of size in switch-mode power supplies and therefore volume reduction and power density raise are beneficial. These switch-mode power supplies consist of two power stages separated by a power transformer with high frequency power. The transformer architecture, which can run at a high frequency, has since become a major challenge for the engineers. Lower component height and better thermal management are advantages with the planar core design. This paper provides a detailed summary of the operating principles of high-frequency transformers. Two transformers are compared in a dual active bridge converter: a wire wound, a planar. This paper discusses a comparison between the wire-wound transformer, high-frequency transformer, and structures in terms of winding loss, core loss, leakage inductance, parasitic capacitance the focus of this research is to find an optimal transform solution for the converter operating at a power level of 220 W. Furthermore, the power losses of a planar transformer are estimated.