Design of broad-band transformers for linear electronic circuits

WHEN DESIGNING LINEAR amplifier circuits, the designers often find it highly desirable to take advantage of the impedance-matching and phase-inverting properties of transformers. However, these designers sometimes fail to realize that even a well-designed transformer may not be able to pass the required band of frequencies when connected between the available power source and specified load. At other times they may ask for impedance or phase characteristics which are unrealistic or which call for unnecessarily close tolerances.