A Dual-Band Unequal Wilkinson Power Divider Using Asymmetric Coupled-Line

In this paper, we present a novel scheme of unequal Wilkinson power divider operating at two arbitrary frequencies. The proposed power divider consists of two isolation resistors, two output matching transformers and two cascading asymmetric coupled-lines, which are used to achieve unequal power division. To investigate the proposed asymmetric coupled structure, in- and anti-phase (c/π-mode) analysis is adopted, instead of conventional even/odd-mode analysis. And analytical design equations are derived based on the transmission line theory. It is found that both frequency ratio and power dividing ratio can be adjusted, respectively. As a typical example, an experimental power divider with the power ratio of 2 : 1 is designed, fabricated and measured. The measured results show good agreements with the simulated ones.