Digital Manufacturing of Pathologically-Complex 3D Printed Antennas

In the last decade, the proliferation of new 3D printing technologies has enabled the fabrication of complex geometries in manifold materials for novel applications. One discipline that has been explored extensively in the context of additive manufacturing is electromagnetic devices such as antennas. Difficult-to-fabricate geometries are now possible and can deliver new antenna functionality and extend performance (e.g., lower frequency resonance in small volumes, wider bandwidth, narrow-beam directionality, and so on). Coupled with accurate 3D electromagnetic simulations, a new paradigm is emerging for antenna design and manufacture. Starting from a seed geometry, the state space can now be explored to identify new combinations and permutations of electromagnetically-beneficial shapes through multiple simulation iterations. Subsequently, the identified structures can be further validated and improved through rapid manufacturing using 3D printing for hardware evaluation in an anechoic chamber. However, to fully benefit from this emerging paradigm, an up-to-date survey of the most recent metal processes is required. This survey would determine which processes are well suited for building the next generation of antennas. For this purpose, a variety of metal 3D printing was employed to fabricate benchmark antennas with pathological geometries, including thin walls, overhanging features, and large aspect ratios. This survey can inform designers about potential structures to serve in novel antennas. A total of five processes have been preliminarily explored including selective laser melting, binder jetting, and plated vat photopolymerization, all of which delivered different advantages and disadvantages in terms of mechanical and electromagnetic performance.