High frequency transformer modeling

This paper presents a technique of indirect measurement of linear and nonlinear elements of a wideband transformer using the reflection coefficient technique with the scattering matrix (S-parameters). The S-parameter frequency domain measurement method of the wideband RF transformer and conversion into a discrete model is discussed. The leakage and the magnetizing inductances, the winding and magnetic losses, and the winding capacitances are calculated using the “parameter extraction” technique. Experimental results of a ferrite wideband transformer over the range 50 to 300 MHz, confirmed that the scattering matrix is a precise and efficient method to obtain a nonlinear transformer model