Circulator

The invention relates to a circulator. A circulator comprises a shell, a center conductor, a rotary magnetic sheet and a permanent magnet are arranged in an inner cavity of the shell, the shell is matched with a cover plate used for sealing an opening of the inner cavity, an adjusting piece is further arranged in the inner cavity, and the adjusting piece or/and the shell is/are provided with a maintaining structure used for maintaining the position of the adjusting piece in the axial direction of the inner cavity. At least the rotary magnetic sheet is limited between the central conductor and the adjusting piece. According to the invention, the height of the inner cavity can be adjusted, so that the set position of the center conductor is not changed under the condition that the shell is not replaced, and parts such as the shell have universality and can be used in circulators with different performance requirements; meanwhile, the method has the advantage that the number and the thickness of the compensation