Compact unequal filtering power divider operating in two bands with controllable characteristic impedances

A design method for unequal filtering power dividers (PDs) working at 2 bands is presented in this article. Compared with conventional unequal PDs, in this method, each section of the proposed circuit uses transmission lines whose characteristic impedances are controllable to avoid high-impedance line. Meanwhile, the conventional lambda/4 transmission line in PDs is substituted with a pair of proper dual-mode resonators. To prove the effectiveness of the proposed design principle, a miniaturized unequal filtering PD working at 3.5 and 4.9 GHz is designed, fabricated and measured. Eventually, it is clear that the simulated results and the measurements have favorable agreement.