Solid freeforming of millimetrewave metamaterials and its applications

Rapid prototyping by an extrusion freeforming technique, of ceramic metamaterials based on a woodpile structure at millimetrewave frequencies has been performed. The proposed method is very versatile and flexible for fabricating various periodic and non-periodic structures in 3-D form. The transmittance of the fabricated millimetrewave EBG structure is measured in the range of 75–110GHz. A high directive millimetrewave antenna using freeformed EBG structure is also presented. Both measurement and simulation results are in good agreement.