In this paper, two antennas for wearable applications are presented, including the development of new antennas on fabric substrates for communication with in-body and outside the body sensors. The design process for fabrication via screen printing on fabric substrates is outlined using commercially available conductive inks. The effects of non-conductive, paint-based inks as interface layers between conductive elements and fabric substrates of coplanar keyhole fabric antennas is presented along with wash sustainability and its effects on antenna resonance at 5.8 GHz over time. Fabrication of screen-printed radio frequency identification tag antenna includes placement of the tag chip. Accessibility of the tag is assessed by comparing reader data to distance between the reader and the tag at 915 MHz.

3D printing is becoming increasingly popular due to its convenience, ease of use, and low cost. Companies such as Ford, General Electric Aviation, and many others are using 3D printing for rapid prototyping before investing time and money in volume manufacturing. However, development in 3D‐printed microwave antennas has remained limited. In this study, a parametric analysis of solely (one step process) 3D‐printed 5.8 GHz patch antennas using commercially available conductive and dielectric materials is presented. Effects of tool path and layer resolution on the substrate material's complex permittivity and radiative material's conductivity are explored. These antennas will utilize commercially available conductive PLA filament (Black Magic) based on graphene as the material for the radiating elements and ground plane. Dielectric PLA will be used in place of the substrate.

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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 glassfilled 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 glassfilled 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 µm. The capacitively coupled disk loaded monopole demonstrates the versatility of 3D printing in antenna fabrication.INDEX TERMS 3D printed antenna, disk loaded monopole, conical horn, metal casting, resin casting