A new design of compact microstrip Wilkinson power dividers

A novel compact microstrip Wilkinson power divider with an easy design and fabrication is proposed in this paper. Through capacitive or inductive loading of both of the quarter-wave transmission lines and the isolated resistor employed in conventional Wilkinson power dividers, reduction of the transmission line segments from λ_g/4 to λ_g/30 is obtained. Therefore, the proposed structure can distinctly save the occupied area. Furthermore, some useful design equations based on odd-even mode analysis for the proposed circuit model are introduced to provide an accurate method to design compact Wilkinson power dividers. The fabricated power divider designed for the frequency of 800MHz is 84% smaller than conventional ones, and has a 120MHz bandwidth for which the input return loss is better than 20-dB. Within this bandwidth, the insertion loss is less than 0.3-dB and the isolation between the outputs more than 20-dB.