A microwave modulation device includes a first radiator; a second radiator disposed on the first radiator; a third radiator disposed on the second radiator; a support structure disposed between the first radiator and the second radiator; and a modulation structure disposed between the second radiator and the third radiator. A microwave-transmission layer is located among the space defined by the first radiator, the second radiator, and the support structure. The microwave-transmission layer is gas, substantially vacuum, liquid or insulating material.