Materials for Use in the Additive Manufacture of RF Components and Devices

Abstract

Additive manufacturing (AM) is a rapidly evolving technology set that has been proven to be a significant value add to a wide range of industries. In the space of RF design and engineering AM has been used for a wide range of applications. However, a lack of printable materials with properties suitable for use in RF applications has limited the performance and frequency range where printed devices can be utilized. At DeLUX Advanced Manufacturing we bring together a unique set of skills from RF engineers, to Mechanical Engineers, to Materials Scientists and Physicists to develop printable materials and deposition techniques specifically for RF applications. In this presentation we will show materials that were developed at DeLUX, in partnership with the University of Delaware, for use specifically in RF applications. We will present characterization data of our line of high dielectric low loss thermoplastic filaments for use in standard fused filament fabrication (FFF) systems. These filaments can have custom tailored dielectric constants ranging from 1.6-8 with loss tangents ranging from 0.0001-0.004. We will also present the use of these filaments in various applications such as, wide steering angle RF graded index (GRIN) lenses, as well as printed antennas on fully printed substrates with discrete spatial dielectric properties. These antennas will also showcase DeLUX’s ability to print integrated RF connectors with performance comparable to commercial of the shelf (COTS) connectors. The conductors for these antennas are also printed using DeLUX developed conductive pastes. These conductive pastes are specially formulated for high conductivity at frequencies up to 30GHz, and for filling long, high aspect ratio, channels and enclosed cavities. Many currently available conductive inks and pastes have greatly reduced conductivities at frequencies greater than a few gigahertz and many cannot be used within tight channels or enclosed spaces due to outgassing during the curing process. High frequency characterization data of these inks will be presented as well as performance data in various printed antenna structures like the stacked dual band patch antenna shown in Figure 1 .