Balun line: Microstrip release

The theory and design of a tapered balun transformer which functions over a wide frequency range is presented. The balun is an impedance-match transition from a microstrip line to a balanced line, formed by two strips with equal width, one strip on each side of the dielectric sheet. Measurements on a test balun show a good performance, both in voltage standing wave ratio and in insertion loss. For its inherent ease of construction and good reproducibility, this type of balun can be utilized in a great number of applications, including the construction of balanced mixes and the excitation of antennas.