A transceiving apparatus may comprise a radiator emitting a beam; a receiver receiving a beam; a first sub-reflector which is provided to face the radiator and changes an orbital angular momentum (OAM) mode order of a beam; a second sub-reflector which is provided to face the receiver and changes an OAM mode order of a beam differently from the first sub-reflector; and a main reflector which is provided to face the first sub-reflector and the second sub-reflector.