Effect of Thickness on Dielectric Properties of 3D Printed TPU Substrate For Patch Antenna Design

Three-dimensional (3-D) printing enables the use of printable materials to fabricate substrates for microstrip patch antennas. Radio frequency (RF) properties of 3-D printed substrates may vary significantly depending on the values of printing parameters used while printing. Therefore, 3-D printed substrates require their RF characterization. This study investigates the effect of substrate thickness on the dielectric constant and loss tangent of 3-D printed Thermoplastic polyurethane (TPU) substrates with two different thickness: 1.6 mm and 3.2 mm. Characterization results are further experimentally validated through the measurement of resonant frequency of two microstrip patch antennas, which were designed based on the RF characterization results. It has been observed that with the increase in thickness of the substrate the values of the dielectric constant and loss tangent parameters decreased.