Microwave characterization of 3D printed conductive composite materials

Abstract

Effective electromagnetic shielding is important for reducing unwanted electromagnetic radiation from high frequency circuits. Recently, electrically conductive (carbon-based) polymer composites have been considered as a viable alternative to traditional electromagnetic interference (EMI) shielding materials due to their light weight, corrosion resistance and ease and flexibility of processing (i.e., three-dimensional/3D printing techniques). As such, in order to be able to take advantage of these benefits, the dielectric properties of these materials at microwave frequencies must be known. To this end, this work considers a set of 3D printed (3-layer) samples consisting of 2 solid outer layers, and an internal mesh layer (with triangular and honeycomb mesh features) with varying polymer volume content. Dielectric measurements were made in the X-band (8.2–12.4 GHz) for the samples with and without the cover layers. The results show that conductive polymers used for 3D printed structures have high potential as another option for EMI shielding structures.