Additively-Manufactured Circuit-Analog Absorbers Printed From Two Materials
Open Access
Author:
Prince, Theodore Jackson
Area of Honors:
Electrical Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
Erik Henry Lenzing, Thesis Supervisor Dr. Julio V. Urbina, Thesis Honors Advisor
Keywords:
Prince Electromagnetics Additive Manufacturing 3D Printing Reflection Complex Permittivity X-Band Ku-Band Polylactic Acid PLA Circuit-Analog Absorber Absorber Materials Characterization Transmission Line Model Metal Powder Graphite
Abstract:
This thesis presents four different additively-manufactured (3D printed) circuit-analog (CA)
absorbers. The CA absorber designs investigated the use of two substrate materials as well as
varying frequency selective surface (FSS) topologies. The complex permittivities of polylactic
acid (PLA), bronze, brass, copper, and iron powder infused PLAs, and a graphite PLA composite
were measured using a free-space materials measurement system. The graphite PLA was selected
for the FSS layer of all absorbers, while iron powder PLA and standalone PLA were selected as
substrates. Complex permittivity data from the selected materials were input to CST Microwave
Studio. Absorber dimensions were optimized using CST’s genetic algorithm. Reflection measurements
of the printed absorbers were made using the free-space measurement system with the
FSS and associated substrate vacuum-bagged to an aluminum ground plane. Measured results
were compared to those from CST and the other prototype absorbers. The results showed that CA
absorber designs fabricated using additive manufacturing are possible.
