Radiation measurements are performed in fully or semi-anechoic chambers or GTEM cells and areusually costly and time-consuming. In addition, most manufacturers of electronic devices do nothave the capability to perform such measurements quickly by themselves. The transfer functionapproach aims at simplifying this problem: once the characteristics of the measurement setup arecaptured in a transfer function, the conducted characterization of the device under test (DUT) issufficient to calculate the results of a radiation measurement. This is justified by the assumptionthat the radiation is mainly generated by the currents on the supply cables and the DUT is smallcompared to the smallest wavelength considered. Additionally, the DUT should behave linearly. Inprevious work [2] it was shown that a characterization of the DUT as a Norton equivalent sourcetogether with the scattering parameters of the measurement setup are sufficient to calculate thevoltage at the received antenna in an anechoic chamber. In this work, the method is applied to abuck converter for both a GTEM cell and a fully-anechoic chamber setup.