Compact filtering power divider with improved out-of-band performance

A compact equal power divider (PD) with filtering function and improved out-of-band performance is proposed in this article. The proposed PD is based on the conventional Wilkinson PD and two filtering cells. The filtering cell is composed of four λ/4 stepped-impedance resonators (SIRs). Using the edge and quasi-lumped coupling topology, a compact PD with improving passband selectivity can be achieved. Meanwhile, by appropriately adjusting the impedance and electric length ratios of SIRs, the stopband can be extended to 39.2 GHz with a rejection level of 20 dB, which is 25 times of the fundamental frequency. The predicted results on S-parameters are compared with the measured ones and good agreement is achieved. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2274–2277, 2015