Design of dual‐band filtering power dividers with designable port‐to‐port isolation network

Abstract

In this article, a class of dual-band filtering power dividers is proposed with simultaneous realization of good designable port-to-port isolation. A filtering branch, including two cascaded stub-loaded half- wavelength resonators and coupled-line sections, are introduced together with the proposed isolation network to simultaneously achieve controllable bandwidth, frequency ratio in dual-band power division, as well as the port-to-port isolation. To construct dual-wideband power division, two coupled multimode resonators could be used to form the filtering branches, while the proposed isolation network with additional open stub at each output port is utilized to obtain a wide port-to-port isolation band. Theoretically, a design method for analyzing the dual-band frequency response of the power division is presented, while a dual- or wide-band isolation is achieved by introducing multiple transmission zeros in the S32-magnitude. Finally, two prototype power dividers on the microstrip-line structure are designed and fabricated. The simulated and measured results agree well with each other, which verify the theoretical predications.