A High-Performance Dual-Mode Filtering Power Divider With Simple Layout

Abstract

This letter presents a simple microstrip dual-mode filtering power divider (FPD) with sharp frequency selectivity and good in-band isolation. A new topology is proposed to integrate only a single resonator and a resistor to realize the dual functions of the power division and filtering. In order to further improve its frequency selectivity and obtain wide upper stopband, three open-ended stubs are integrated into the input and outputs of the FPD, respectively. The presented FPD stands out from those in the literature, by both improved performance and simple design layout. For validation, a prototype FPD operating at 2.2 GHz with 3-dB fractional bandwidth of 18.2% is designed and fabricated. The experimental results agree well with the simulated ones. The results indicate that the new FPD exhibits better than 32-dB in-band isolation along with 24-dB harmonic suppression up to 6.28 GHz ( $2.85~f_{0}$ ).