A Novel Modified Dual-Frequency Wilkinson Power Divider with Open Stubs and Optional Isolation

Abstract

This paper presents an approach to the design of a novel dual-band power divider with variable power dividing ratio. In the matching structure, two parallel open circuit stubs can be used in input port, which are introduced to reduce the return loss and improve matching characteristics. In the isolation structure, two transmission lines and a single resistor are applied, and the design values are adjusted according to the center frequency ratio. In this proposed power divider, the ideal matching of all ports, equal power splitting and isolation between the output ports can be achieved. Closed-form design equations with one electrical length of design freedom are derived using conventional even- and odd-mode analysis and transmission line theory. Moreover, by solving the final nonlinear design equations, accurate numerical design data along with different frequency ratios are obtained, and the effective normalized parameters are given simultaneously in figure and table formats for specific applications. Three cases with simulation results are presented firstly. And then, in microstrip experiments, simulated and measured results of two fabricated power dividers with different frequency ratios are given. It can be clearly seen that there are good consistency between the theoretical and experimental results.