A passive circulator , comprising: a pair of ferrite plates; each of the ferrite plates having a first saturation magnetization and an edge portion having a second saturation magnetization that is lower than the first saturation magnetization; a magnet assembly including a pair of cylindrical magnets disposed relative to the ferrite plates to provide a static magnetic field to the ferrite plates to magnetize the ferrite plates, the ferrite plates disposed between the pair of magnets and the magnetization configured to facilitate transmission of a radio-frequency signal between first and second locations along the perimeter of the ferrite plates based on a standing wave pattern formed in the ferrite plates due to the magnetization; a magnetic circuit configured to provide a return path for the magnetic field, the magnetic circuit including a pair of disks having a diameter larger than the diameter of the cylindrical magnets, the magnets disposed between the pair of disks, and at least one hollow cylinder having an inner diameter that matches the diameter of the pair of disks; the return path passing through one of the pair of disks , then through one of the pair of magnets , then through the pair of ferrite plates , then through the other of the pair of magnets , then through the other of the pair of disks , and then through the at least one hollow cylinder ; and first and second electrical conductors, each forming a port that is positioned equally spaced azimuthally around the circulator, disposed relative to the first and second locations so as to facilitate the transmission of radio-frequency signals between the first and second locations. a pair of ferrite plates; each of the ferrite plates having a first saturation magnetization and an edge portion having a second saturation magnetization that is lower than the first saturation magnetization; a magnet assembly including a pair of cylindrical magnets disposed relative to the ferrite plates to provide a static magnetic field to the ferrite plates to magnetize the ferrite plates, the ferrite plates disposed between the pair of magnets and the magnetization configured to facilitate transmission of a radio-frequency signal between first and second locations along the perimeter of the ferrite plates based on a standing wave pattern formed in the ferrite plates due to the magnetization; a magnetic circuit configured to provide a return path for the magnetic field, the magnetic circuit including a pair of disks having a diameter larger than the diameter of the cylindrical magnets, the magnets disposed between the pair of disks, and at least one hollow cylinder having an inner diameter that matches the diameter of the pair of disks; the return path passing through one of the pair of disks , then through one of the pair of magnets , then through the pair of ferrite plates , then through the other of the pair of magnets , then through the other of the pair of disks , and then through the at least one hollow cylinder ; and first and second electrical conductors, each forming a port that is positioned equally spaced azimuthally around the circulator, disposed relative to the first and second locations so as to facilitate the transmission of radio-frequency signals between the first and second locations. <EOS>