Wideband filtering power dividers with wide stopband rejection

Abstract

AbstractA series of novel wideband filtering power dividers (WFPDs) with wide stopband rejection performances is proposed in this paper. The proposed WFPD structure consists of a parallel-coupled line, two transmission line (TL) sections, four loading terminations, and an isolation resistor. The coupled line is applied at the input port to provide wideband impedance transformation, while different types of loading terminations and TL sections are adopted to realize various out-of-band rejection performances. To verify the proposed concepts, three WFPDs operating at 3.0 GHz are designed and fabricated with 3 dB bandwidth of 79.7, 79.0, and 74.4%. In WFPD1, the measured out-of-band rejection of better than 13.4 dB extends to 2.57f0. Moreover, the measured out-of-band rejection of better than 17 dB extends to 2.47f0 (4.75f0) in WFPD2 (WFPD3), respectively. Good agreements between the simulated and measured results validate the presented ideas.