3D printing of electromagnetically functional materials for radio frequency applications using fused filament fabrication

The fabrication of radio frequency (RF) devices using various 3D printing technologies has gained significant momentum. Among these, Fused Filament Fabrication (FFF) stands out as a cost-effective method, yet its potential for RF applications remains underexplored. This review comprehensively examines recent progress in this field, with a specific focus on the critical role of functional filaments. The discussion is structured around material innovations, including ceramic filaments for enhancing dielectric properties, as well as conductive filaments (metal- and carbon-based) for integrated passive components and transmission lines. By synthesising the current state of the art, this review identifies key manufacturing and performance challenges and proposes promising future research directions to unlock the full potential of FFF for next-generation RF applications.