An ultra‐wideband and sharp‐selectivity filtering power divider with modified three‐line coupled structure

This is the authors' abstract. We don't add key points for this paper.

An ultra-wideband filtering power divider (FPD) with miniaturized sized is proposed in this article. In order to improve the selectivity of the filter, modified stepped impedance resonators (SIRs) are utilized to generate two transmission zeroes nearby the passband. Moreover, three transmission poles within the passband are introduced with the modified SIR structure and the short-circuit stubs, which can enlarge the bandwidth of the proposed FPD circuit. An equivalent circuit model is built to interpret the mechanism of the presented FPD design. Finally, a prototype of the wideband FPD structure centered at 3.34 GHz is designed, fabricated and tested with 3-dB fractional bandwidth of 95.2%. A sharp selectivity of 52.9 dB/GHz is also observed. The measured results agree well with the simulated predictions.