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

ABSTRACT 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