Date of Graduation

5-2022

Document Type

Thesis

Degree Name

Bachelor of Science in Electrical Engineering

Degree Level

Undergraduate

Department

Electrical Engineering

Advisor/Mentor

El-Shenawee, Magda

Committee Member/Reader

Ware, Morgan

Abstract

3D printers are a method of additive manufacturing that consists of layering material to produce a 3D structure. There are many types of 3D printers as well as many types of materials that are capable of being printed with. The most cost-effective and well documented method of 3D printing is called Fused Deposition Modeling (FDM). FDM printers work by feeding a thin strand of plastic filament through a heated extruder nozzle. This plastic is then deposited on a flat, typically heated, surface called a print bed. The part is then built by depositing thin layers of plastic in the shape of the cross sectional area of the part. The print time of 3D printed parts typically takes anywhere from 15 minutes to a couple days, depending on complexity. FDM printers are capable of printing almost any shape that fits within the print volume of the machine without special tooling. Therefore, 3D printers can be used to rapidly prototype complex designs and are capable as a production method in and of itself. This thesis focuses on the finding the real and imaginary components of the complex permittivity of three common 3D printed plastics in the W-Band (75 GHz - 110 GHz): Polylactic Acid (PLA), Acrylonitrile Butadiene Styrene (ABS), and Polyethylene Terephthalate Glycol (PETG). The Free Space System is used to measure the S11, S12, S21, and S22 parameters of a flat sample of the plastics from 75 GHz to 110 GHz. The obtained results demonstrate that the relative permittivity of each sample remains relatively stable across the entire bandwidth of the frequencies tested. PLA has the highest relative permittivity out of all the samples at 2.724 and the PETG has the lowest permittivity at 2.675. The permittivity of these 3D printed materials are slightly higher than that of Teflon which has a real relative permittivity of 2.1. Furthermore, the imaginary part of the permittivity that represents the losses in the material are shown to be small (below 0.045 for all samples) between 75 GHz - 110 GHz.

Keywords

3D Printing, W-Band, Relative Permittivity, PLA, ABS, PETG, Free-Space System

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