Design of the semi-lump bandpass Wilkinson power divider

The semi-lump bandpass Wilkinson power divider using PI capacitor network integrated with end shorted coupled line sections are proposed. This configuration not only enhances the frequency selectivity of divided transition paths, but also is benefit for circuit miniaturization. Besides, the design equations for isolation resistance are also derived from the theory of narrowband filter analysis. The circuit is implemented on two metal layers FR4 PCB with center frequency located at 3.6GHz with 600MHz effective bandwidth. The measured results reveal that the insertion loss which is lower than 3dB and isolation which is higher than 20dB can be reached.