A new class of wideband differential phase shifters employing two distinctive multimode resonators both in main and reference lines is presented. Compared with their counterparts, the proposed phase shifter firstly can achieve wideband phase shift and good filtering function with controllable same insertion loss (IL) bandwidth in main and reference lines as required. To design two phase-shifting elements with design indices (phase-shift value, return loss, and operating bandwidth), an effective synthesis method is presented and sets of design curves are graphically demonstrated. Prototype phase shifters are then fabricated and measured. Finally, the design approach is validated experimentally. It is shown that the proposed phase shifters achieve 90 degrees +/- 2.3 degrees and 45 degrees +/- 2.0 degrees over the prescribed band 2.26-3.72GHz (48%) and 2.04-4.03GHz (66%). The good frequency selectivity with the same IL bandwidth is obtained and out-of-band rejection is >30.2 and 26.4dB up to 7.0GHz.