Design of Compact Dual-Band Power Dividers With Frequency-Dependent Division Ratios Based on Multisection Coupled Line

In this paper, a design method of compact dual-band power dividers with frequency-dependant power division ratios in two separated bands is proposed. A multisection coupled-line scheme is presented that takes advantage of the different odd- and even-phase velocities of a microstrip implemented coupled line. The proposed method is applicable to an extended frequency ratio of 1.4-3 compared to the formerly investigated coupled-line dual-band transformer. The design procedures are demonstrated by two design examples, and measurements of the implemented circuits are made for verification.