Recently, as the science of materials has greatly advanced, the achieved results have changed the conventional vision of the intrinsic properties of materials such as chiral and metamaterial. An important class of existing microwave devices takes advantage of the bianisotropic materials phenomena and properties for the development of innovative devices that respond to the needs of modern technologies. In this scope, we have investigated the bianisotropic Tellegen medium used as a substrate for a printed dipole antenna; a complex material that is less addressed in the literature. Numerical studies are based on the development of the spectral Green’s functions and the method of moments is used to solve for the electromagnetic field components and the dipole input impedance. The behavior of the magnetoelectric elements of the Tellegen medium is highlighted by analyzing their effect on the electromagnetic field distribution and input impedance. Initial results reveal a negative real part of the dipole input impedance for some values of the magnetoelectric elements. A result that should be viewed in the light of unusual behavior of synthetic materials such as negative refractive index in metamaterials. An elementary explanation for this behavior is presented based on the analysis of the electromagnetic field distribution.