Quality Factor Estimation of Additively Manufactured Frequency Selective Surfaces via Active Microwave Thermography

Additive manufacturing (AM) has increased in popularity in recent years due to improvements in efficiency over traditional manufacturing methods. Furthermore, the availability of electrically conductive fused deposition modeling (FDM) filaments has opened the door to the manufacture of conductive structures, including frequency selective surfaces (FSSs). Traditionally, the performance of an FSS is verified experimentally through electromagnetic (EM) measurement of the FSS’s reflection and/or transmission response. However, this verification approach is not ideal for rapid, in situ inspections due to the time-consuming measurement process, expensive and complicated equipment, and difficult to interpret results. To this end, active microwave thermography (AMT), a coupled EM-thermographic measurement technique, is considered as an alternative, rapid inspection approach. Traditional FSS and AMT measurements were completed on a set of five AM-FSS specimens. The results indicate the potential for AMT to be used in place of traditional FSS measurements for rapid inspection of AM-FSSs and similar conductive structures.