Indirect Applications of Additive Manufacturing for Antennas

We report the fabrication methodology of stereolithography (SLA) printed molds for metal and resin cast antennas. In the first method, a conical horn created using metal cast molds printed from a glass-filled resin utilizes a casting technique allowing for low-cost 3D printing to fabricate metal antennas, reducing the losses incurred by metallized plastics, while still producing complex geometries quickly. This metal cast conical horn is compared to a horn constructed using a more traditional 3D printing method. The second casting method demonstrates the interchangeability between creating parts via SLA printing with a glass-filled resin and using the same resin cast into a reusable Polydimethylsiloxane (PDMS) mold. We demonstrate this method by casting an interchangeable slug for a capacitively coupled, mechanically reconfigurable disk loaded monopole. Simulated and experimental data are presented for S11, and Gain. Simulated BW, directivity, gain and efficiency as a function of frequency are presented. The results indicate that the 3D printed metal casting process produces antennas with a higher gain and lower return loss than metallized resin antennas. The method is suitable for difficult geometries requiring resolution of at least 50 lm. The capacitively coupled disk loaded monopole demonstrates the versatility of 3D printing in antenna fabrication.