A Novel Balanced-to-Unbalanced Complex Impedance-Transforming In-Phase Power Divider

In this paper, a simple and compact planar balanced-to-unbalanced in-phase power divider with arbitrary terminated impedances is proposed based on the coupled-line structure and a single grounded resistor. By using the even-/odd-mode analysis and the traditional transmission-line theory, the complete design procedure and analytical equations are obtained to achieve good performances for differential-mode transmission, common-mode suppression, phase difference, arbitrary terminated impedances, and isolation. For demonstration, two different prototypes with 50-to-50 Ω matching and complex impedance transformation are designed, fabricated, and measured. Good agreement can be observed between simulated and measured results.