Design and implementation of microstrip dual-band filtering power divider using square-loop resonator

This Letter presents a dual-band filtering power divider (FPD) by employing square-loop resonator loaded by open stubs. The even-and odd-mode equivalent circuits of the proposed resonator are analysed and design equations are derived. For demonstration, the power divider (PD) is fabricated and measured. The simulated results of the PD not only show a good selectivity but also it does good isolation. Finally, the comparisons of the measured and simulated results of the dual-band FPD are presented, which are in good agreement. The measured results show that the dual-band FPD has better than -30/-36 dB isolation, -16.5/-18 dB return loss, and -3.9/-4.0 dB insertion loss at centre frequencies of 3.1 and 5.3 GHz, respectively.