In this paper, details of designing a four-opening broadband active circulator are investigated. The proposed model works in the 2-26GHz frequency band and also amplifies the output wave to 11.35 ± 0.018, which is one of the advantages of the designed model. Common circulators are passive ones with disadvantages of the limited bandwidth, frequency dependency and large dimensions in the case of large number of openings. Also, either increasing or decreasing the number of openings requires redesigning of the circulator. However, for the proposed model in this paper, the bandwidth is increased, the dimensions are reduced and the number of craters can easily be changed. Manuscript profile