Dual-band balanced-to-unbalanced out-of-phase equal power divider

This article proposes a Gysel type dual-band balanced-to-unbalanced (BTU) power divider (PD) for equal power division. The proposed PD has out-of-phase (phase difference between two output signal is 180 degrees) characteristic. Standard [S] matrix for the dual-band PD is derived from mixed mode [S] matrix. Analysis is carried out to obtain design equations of the PD. The proposed PD is designed for a frequency ratio of 1.91. The two design frequencies are 2.2 and 4.2 GHz. A prototype is fabricated to validate theory and design equations. Measurement results show the dual-band nature and out-of-phase characteristic of PD. Size of the fabricated prototype is 0.52g x 0.29g. The proposed PD configuration can also be used for high power application.