A Square Coaxial Transmission Line With Partially Filled Low-Cost 3-D Printing Insulator

This paper presents a square coaxial transmission line that is partially filled with 3-D printing low-cost insulator. The proposed coaxial line is composed of two metal conductors and 3D printing insulator. To reduce the dielectric loss, the space between two conductors is partially filled with 3-D printing insulator. Herein, the insulator is the resin whose cost is lower than conventional PTFE, and the relative permittivity and loss tangent are measured first. Then, the guide-wave characteristic of the proposed transmission line is studied. Finally, a transmission line with two transitions is designed and simulated to verify the analysis.