Design of wideband filtering phase shifters with wide stopband

Abstract This letter presents a class of wideband filtering phase shifters using end coupled short-circuit resonators (ECSCRs). By employing parallel coupled line, transmission zero (TZ) can be introduced. The proposed ones have some advantages such as intrinsic wideband characteristic, steep filtering property, wide stopband bandwidth, and low phase deviation in phase shift. The synthesis method for designing the proposed wideband filtering phase shifters with a prescribed phase shift value and bandwidth is presented. To verify the design method, 45° and 90° wideband filtering phase shifters are designed, fabricated, and measured. Good performances are achieved with small insertion loss and low phase deviation of ± 2.2° over bandwidth of 56.64 %, and 62.69 %, respectively.