Evaluation of Microwave Characterization Methods for Additively Manufactured Materials

Abstract

Additive manufacturing (AM) has become more important and common in recent years. Advantages of AM include the ability to rapidly design and fabricate samples much faster than traditional manufacturing processes and to create complex internal geometries. Materials are crucial components of microwave systems and proper and accurate measurement of their dielectric properties is important to aid a high level of accuracy in design. There are numerous measurement techniques and finding the most appropriate method is important and requires consideration of all different factors and limitations. One limitation of sample preparation is that the sample size needs to fit in the measurement method. By utilizing the advantage of additive manufacturing, the material can be characterized using different measurement methods. In this paper, the additive manufacturing process and dielectric measurement methods have been critically reviewed. The test specimens for measuring dielectric properties were fabricated using fused filament fabrication (FFF)-based additive manufacturing and were measured using four different commercial dielectric properties measurement instruments including split post dielectric resonator (SPDR), rectangular waveguide, TE01δ cavity resonator, and open resonator. The measured results from the four techniques have been compared and have shown reasonable agreement with measurements within a 10 percent range.

All‐Dielectric Toroidal Metasurfaces for Angular‐Dependent Resonant Polarization Beam Splitting

“…In order to isolate the effect of the losses, we evaluate the PBS performance of the AMS in Figure a, by artificially varying the PLA loss tangent, spanning a range compatible with microwave substrates, either 3D‐printable (e.g., acrylonitrile butadiene styrene and high‐impact polystyrene) or standard (such as polytetrafluoroethylene at the low‐loss edge). [ 45,46 ] A loss tangent of 0.001 increases the transmittance above , whereas its further reduction by one order of magnitude has negligible impact. A way to further suppress the IL is by using a low‐permittivity microwave foam.…”

“…This value was retrieved by characterizing a solid plate of the used 3D‐printed material through X‐band waveguide measurements (details in Section S2, Supporting Information), and it is aligned with other reported measurements of PLA permittivity. [ 45,46 ] The measured loss tangent of 0.01 is in the order of standard microwave substrates, such as FR4. A detailed analysis on the effect of the substrate dielectric losses will be provided in Section 5.…”

The Impact of 3D Printing Process Parameters on the Dielectric Properties of High Permittivity Composites

“…The dielectric properties of the additively manufactured samples were determined by placing the printed samples of 22.86 × 10.16 × 2.5 mm size, into an X-band waveguide cavity (8.2-12.4 GHz), measuring the transmission and reflection from the target sample, connected to a Vector Network Analyser (VNA) (MS465B22, Anritsu, Japan) using coaxial cables. Relative permittivity (ε r ) and loss tangent (tanδ) were calculated using the Nicolson-Ross-Weir method [13]. All reported measurements are reported as an average out of 5 different 3D printed samples together with standard error.…”

Dual Coaxial Probes in Transmission Inserted by Dielectric With Two Different Thicknesses to Extract the Material Complex Relative Permittivity: Discontinuity Impacts

“…Material characterization has a wide variety of characterization techniques depending on the application domain [1], increasing the different degrees of understanding [2,3]. Other material techniques are investigated in several laboratories to better understand the different material properties and behaviors [2,4,5].…”