Abstract: An isolator/circulator can keep a size of a 3-way asymmetric propeller resonator and intensity of magnetism, control the preferred frequency, and improve the insertion loss and isolation characteristic due to reducing the ferrite usage region on the maximum, extend the wide band without the external wide band extension, finally to miniaturize, reduce the fabricating cost by means of a simple fabrication. A microstrip/stripline isolator/circulator having a propeller resonator can be used for the device protection and impedance matching of a system and terminal in a transfer communication, personal communication, CT and satellite communication.