Investigation of the 3D Printing Roughness Effect on the Performance of a Dielectric Rod Antenna

In this letter, the roughness effect of a three-dimensional (3-D) printed dielectric rod antenna is investigated. One of the issues of 3-D printing in microwave components and antennas is the limited printing resolution, which creates a surface roughness on printed devices and deteriorates the performance. The effect of surface roughness on the radiation characteristics and impedance matching of a dielectric rod antenna is studied. The roughness as a perturbation brings the antenna out of its optimum design by changing the E-field intensity alongside the rod. The whole antenna consisted of a coaxial to waveguide adapter and the dielectric rod is 3-D printed and the adaptor is dipped into a low viscosity solution of silver epoxy and isopropanol to coat a conductor layer on the inner surfaces of the waveguides. The fabrication method is cost effective and much easier than conventional methods.