3-D Printing Assisted Micromachined RF Patch Antenna

Abstract

This paper presents a three-dimensional (3-D) printing assisted microfabrication of RF patch antenna. As the 3-D printing can provide more flexibility of the structural design, this paper introduces the combined fabrication methods of the metal patterning by conventional micromachining processes on the 3-D printed frames for a patch antenna. Challenges of the combined fabrication processes include; (1) the 3-D printed material has to be well defined to predict the RF loss or performance in particular with the effective dielectric constant, (2) the printed surface smoothness should satisfy for minimizing RF losses, and (3) microlithography process should be compatible with the 3-D printed substrate. To address the material property and define the effective dielectric constant, a ring resonator was designed, fabricated, characterized on the flat 3-D printed substrate. In the fabrication, a 10-μm gap between the feeding line in the ring resonator was successfully micromachined on the 3-D printed substrate. The surface smoothness was improved by an additional spray coating on the 3-D printed frame. A customized 3-D printed shadow mask process enabled the micropatterning process to form a 3-D shape patch antenna. The proposed fabrication process has great potential for various 3-D antennas, waveguides, and other RF components.