Comparison of Methods for Dielectric Characterization of Additively Manufactured Materials

As additive manufacturing (AM) gains traction in the field of antennas, characterizing the electromagnetic properties of AM materials becomes paramount for comparison to simulation and modeling. The Nicholson-Ross-Weir (NRW) and reference-plane invariant (RPI) methods are two well-known algorithms used for the extraction of complex permittivity from S-parameters of material samples measured in a waveguide. This paper gives a brief overview of the two methods and then compares the measured complex permittivity of various AM samples.