Multifunctional Multiband Filtering Power Dividers With Adjustable Frequencies and Bandwidths

This paper presents a novel design for multifunctional multiband filtering power dividers (FPDs) with independently adjustable center frequencies and bandwidths. Specifically, the design uses multiple pairs of miniaturized dual-mode stub-loaded resonators for compactness and to achieve flexible passband allocation. Independently controlled coupling paths for each frequency band are used to allow for individual passbands to be tuned separately without introducing additional complexity. Two prototypes, namely a dual-band FPD and a triband FPD, were fabricated on a Rogers RO4003 substrate to validate the proposed design. The design’s equal power division capability, low loss, high port-to-port isolation, and well-balanced magnitude and phase responses were indicated by a close agreement between simulation and empirical results. The proposed circuits have an advantage over other multiband FPDs in terms of size, electrical characteristics, and scalability, making them highly suitable for modern multiband wireless communication systems.