Wideband Filtering Unbalanced-to-Balanced Independent Impedance-Transforming Power Divider With Arbitrary Power Ratio

In this paper, a novel wideband filtering unbalanced-to-balanced power divider is proposed. A generalized circuit model for arbitrary power ratio and independent impedance-transforming function is constructed based on the modified even-/odd-mode analysis. Thus, closed-form analytical equations and complete design procedures are provided. Furthermore, the introduced open-circuited stubs are loaded at the output ports to improve the frequency selectivity. Finally, two 2:1 unequal designed prototypes with the 10-dB relative bandwidth of 52% and 65% at the center frequency of 2 GHz are fabricated and measured. A good agreement between electromagnetic simulation and measured results is observed, which demonstrates the validity of the proposed design method and the circuit model.