Characterisation of 3D printed meta-structure PLA substrate for patch antenna applications in S-Band

A novel approach for the dielectric characterisation of 3D printed substrates in S-band applications of patch antennas with different infill percentages is presented in this paper. The meta-structure substrate design has been 3D printed with a fused deposition modelling technique using bio-sourced material poly-lactic acid (PLA). Combining different infill patterns changes the dielectric parameters, and hence, the RF(Radio-Frequency) performance of the design. To validate the usefulness of this approach, the Taguchi sampling technique is used, where nine samples of a meta-structure substrate were designed to determine the dielectric properties of the substrate. The ring resonator technique is used for measuring the dielectric constant and loss tangent of the fabricated substrates. All nine meta-structure substrate shows varying dielectric properties, which can be used for tuning of RF characteristics of the patch antenna. The measured permittivity of various substrate structures ranges between 2.39 and 2.71. The concept of propagation delay is chosen as the selective parameter for the fabrication of the antenna. The results of antenna simulation and fabrication were mapped closely. The proposed meta-structure design antenna resonates at 2.43 GHz with an S-11 of -26.60 dB. Gain enhancement of 5% is seen in the selected meta-structure design compared with the simple (solid) structure. This meta-structure substrate design approach using different patterns is simple, scalable and can be realised in other 3D printed antenna applications.