A transmission line impedance transformer including at least two different dielectric media having different dielectric properties, each of the dielectric media being configured to taper in thickness along the length of the impedance transformer in an inverse relationship with respect to each other so as to form a combined dielectric medium having an effective dielectric property that is graded along the transmission path. The two or more dielectric media may be disposed between two conductors to provide an impedance transformer in which a characteristic impedance of the transmission line varies along its length in response to the gradation of the effective dielectric property of the combined dielectric medium.