Abstract: The invention provides a balun for coupling an unbalanced device with a balanced device. The balun may, for example, comprise an unbalanced balun structure having a first unbalanced component and a second unbalanced component electrically coupled to one another and a balanced balun structure having a first balanced component and a second balanced component. The first balanced component electromagnetically couples more than one side of the first unbalanced component and the second balanced component electromagnetically couples more than one side of the second unbalanced component. The unbalanced and balanced components may comprise conducting strips, such as strip lines, disposed on a dielectric layer. The balun may be formed on multiple layers or only a single layer. The balun receives unbalanced signals and outputs balanced signals, i.e., signals with a 180-degree phase shift and vice versa.