Dielectric Properties of a Low-Permittivity Composite Dielectric Material

Rapid advances in telecommunication systems operating at frequencies of 30 GHz and above (including 5G systems) require that materials having a dielectric constant under 2.2 and compatible with printed circuit board technology be designed and produced. Technological approaches to the fabrication of such materials build on forming air cavities in a starting dielectric matrix and require control over their microwave parameters (primarily over their dielectric permittivity and dielectric loss tangent) in the frequency range of interest. In this paper, we report our findings on the dielectric properties of a low-permittivity composite dielectric material. Hermetically sealed dielectric plates with a particular distribution of air cavities over their bulk were fabricated using mechanical perforation and 3D printing additive technology. Microwave parameters of the specimens obtained were determined at a frequency of ~10 GHz using a dismountable cylindrical resonator. We studied specimens with a minimum dielectric permittivity of 1.75. It has been shown that, because of a number of specific features, the use of 3D printing additive technologies leads to changes in the geometric dimensions of forming air cavities, which in turn influences the dielectric properties of the material. The results obtained in this study can be useful in designing new microwave materials.