3D-Printed Microwave Encoders based on Embedded and Buried Dielectric Inclusions

Abstract

In this paper, 3D-printed permittivity contrast microwave encoders based on embedded and buried dielectric inclusions are presented. The inclusions, made of a high, or low, dielectric constant material as compared to the one of the host substrate, are square shaped, so that they can be easily detected by means of a dedicated reader based on a permittivity sensor. By embedding the inclusions in the host substrate during encoder fabrication, rather than printing them on top of it, we avoid protuberances that may jeopardize encoder robustness against mechanical wearing (i.e., friction). Moreover, it is demonstrated that encoder functionality is preserved by burying the inclusions in the host substrate. By this means, the inclusions are not visible, and this provides system security for identification applications. The proposed encoders are also useful for the measurement of linear displacements and velocities.