A transformer includes a bobbin, a primary coil, and a pair of secondary coils. The bobbin has an axial bore formed therein. The primary coil is wound on the bobbin and is adapted to be electrically excited with an excitation signal. The secondary coils are disposed adjacent to the primary coil, and are inductively coupled to the primary coil upon electrical excitation of the primary coil. The primary coil is wound on the bobbin such that at least a portion of the primary coil has a cross section shape that is a trapezoid.
