Compact Filtering Power Divider With Enhanced Second-Harmonic Suppression

This letter presents a compact power divider integrated with high-selectivity bandpass resoponses. A novel topology is proposed to integrate five resonators and a resistor to realize the dual functions of the power division and filtering. Two transmission zeros are generated near the passband edges and another one is created at the second harmonic frequency which enhances the rejection levels. For validation, a filtering power divider operating at 920 MHz is implemented with more than 20 dB isolation. The circuit size is 0.15 λ_g×0.14 λ_g, featuring compact size.