Proposal and Design of a Power Divider With Wideband Power Division and Port-to-Port Isolation: A New Topology

In this article, a novel topology is proposed to design a class of power dividers with the simultaneous realization of wideband power division and port-to-port isolation. On the one hand, in order to achieve a wideband power dividing response, two wideband filtering branches, including multimode resonators and parallel-coupled lines, are formed to replace the quarter-wavelength impedance transformers in the Wilkinson power divider. On the other hand, two output ports are at first electrically connected in shunt, stretched by quarter-wavelength transmission lines and then shunt-connected via one resistor, aiming to achieve the highly desired wideband port-to-port isolation. After the theoretical analysis on frequency responses of power division and port-to-port isolation is carried out, a prototype power divider on the microstrip-line structure is designed and fabricated. Good agreement between the simulated and measured results is obtained, exhibiting an extremely wide operating band of 78% fractional bandwidth, over which 3 +/- 0.3-dB power division and 17.5-dB port-to-port isolation have been simultaneously achieved.