Comments on "Compact Broadband Gysel Power Divider With Arbitrary Power-Dividing Ratio Using Microstrip/Slotline Phase Inverter"

In the above paper, the authors present a compact broadband Gysel power divider with an arbitrary power-dividing ratio. The broadband feature of the circuit is obtained by combining the dual-band four-branch-line structure and the ideal 180° phase shifter, as shown in Fig. 1. As in our study, a dual-band rat-race coupler with an arbitrary power dividing ratio is presented.